15

Common

This SOM can reduce the host response time to be within about 6 seconds.

Notes:

1. This mode is used on a storage system where slow or delayed drive response may affect business operations.
2. When Dynamic Sparing or Auto Correction Mode is used, because host I/Os conflict with copy processing, the I/O watching time is 30 seconds even when this SOM is set to ON.
3. Even though SOM 15 is set to ON, the function does not apply to SATA or NL-SAS drives.
4. When SOM 771 or SOM 797 is set to ON, the setting of SOM 771/797 is prioritized for the read I/O watching time.
5. When this SOM is applied, SOM 142 is disabled.
6. For additional details about this SOM (interaction with other SOMs, operational details), contact customer support (see SOM015 sheet).

ON

-

22

Common

Regarding the correction copy or the drive copy, in case ECCs/LRC PINs are set on the track of copy source HDD, SOM 22 can be used to interrupt the copy processing (default) or to create ECCs/LRC PINs on the track of copy target HDD to continue the processing.

Mode 22 = ON: If ECCs/LRC PINs (up to 64) have been set on the track of copy source HDD, ECCs/LRC PINs (up to 64) will be created on the track of copy target HDD so that the copy processing will continue. If the number of ECCs/LRC PINs exceeds 64, the corresponding copy processing will be interrupted.

Mode 22 = OFF: If ECCs/LRC PINs have been set on the track of copy source HDD, the copy processing will be interrupted. (First recover ECCs/LRC PINs by using the PIN recovery flow, and then perform the correction copy or the drive copy again).

One of the controlling option for correction/drive copy.

OFF

None

80

ShadowImage

In response to the Restore instruction from the host, if neither Quick nor Normal is specified, the following operation is performed.

Mode 80 = ON: Normal Restore / Reverse Copy is performed.

Mode 80 = OFF: Quick Restore is performed.

Notes:

1. This mode is applied when the specification for Restore of SI is switched between Quick (default) and Normal.
2. The performance of Restore differs depending on the Normal or Quick specification.

OFF

-

87

ShadowImage

Determines whether NormalCopy or QuickResync, if not specified, is performed at the execution of pairresync by CCI.

Mode 87 = ON: QuickResync is performed.

Mode 87 = OFF: NormalCopy is performed.

OFF

-

122

ShadowImage

ShadowImage for Mainframe

For Split or Resync request from the Mainframe host and Storage Navigator.

Mode 122 = ON: By specifying Split or Resync, Steady/Quick Split or Normal/Quick Resync is respectively executed in accordance with Normal/Quick setting.

Mode 122 = OFF (default): By specifying Split or Resync, Steady/Quick Split or Normal/Quick Resync is respectively executed in accordance with Normal/Quick setting.

For details about pairsplit/pairresync command behavior, contact customer support (see SOM122 sheet).

Notes:

1. Executing the pairresync command from CCI may be related to the SOM 87 setting.
2. When performing At-Time Split from CCI, set this mode to OFF, or specify the environment variable HORCC_SPLT for Quick. Otherwise, Pairsplit may turn timeout.
3. This mode becomes effective after specifying Split/Resync following the mode setting. The mode function does not work if it is set during the Split/Resync operation.

OFF

-

142

Common

When a command issued to a drive turns to time-out, the failure is counted on the failure counter of the drive port. If the failure counter reaches the port blockage threshold, the drive port is blocked. When this mode is set to ON, the port is blocked when the number of failures reaches the half point of the threshold, which mitigates the occurrence possibility of the host time-out.

Mode 142 = ON: The threshold value of blocking a drive port due to command time-out is changed to the half of the normal threshold.

Mode 142 = OFF: The threshold value of blocking a drive port due to command time-out does not change.

The default setting for this mode depends on the microcode level:

• Default = ON: 80-04-27 and later (within 80-04-xx range), 80-05-05 and later, 83-04-03 and later
• Default = OFF: earlier than 80-04-27 (within 80-04-xx range), earlier than 80-05-05 (within 80-05-0x range), earlier than 83-04-03

Notes:

1. This mode should always be set to ON. This mode can be set to OFF only when the customer does not allow to set the mode to ON for a storage system already in production.
2. The mode is effective for the entire storage system.

ON (depends on microcode level)

-

144

Common

The drive whose command response time is permanently delayed is blocked. At the same time, SSB=AE4A (total response time exceeds threshold) is reported. In this case, cache can become overloaded so that the storage system performance is degraded.

Mode 144 = ON: Check if there is a permanently delayed drive for each port, and block the corresponding port at the first time when all of the following conditions are met:

1. The total time for the drive to respond to 200 commands is 20 seconds or more.
2. The response time of the drive is two times or more longer than the average response time of the parity group (excluding the slow drive).
3. The drive is in one of the following statuses:

   - Normal

   - A source drive or a target drive (spare drive) during drive copy.

   - A target drive (not spare drive) during copy back.

   - A target drive (spare drive) during correction copy.

Mode 144 = ON: Checking for delayed drives is not performed.

The default setting for this mode depends on the microcode level:

• Default = ON: 80-04-27 and later (within 80-04-xx range), 80-05-05 and later, 83-04-03 and later
• Default = OFF: earlier than 80-04-27 (within 80-04-xx range), earlier than 80-05-05 (within 80-05-0x range), earlier than 83-04-03

Note: If there are multiple response-delayed drives in the same parity group, only the first one is blocked.

ON (depends on microcode level)

-

310

Common

Mode 310 = ON: The monitoring timer for MP hang-up is 6 seconds and returning a response to the host within 8 seconds is guaranteed.

Mode 310 = OFF: The monitoring timer for MP hang-up is 8 seconds.

Notes:

1. This mode applies to a site where strict host response performance is required.
2. If a hardware failure occurs when the mode is set to ON, the time until MPB blockage is determined is shorter than usual.

OFF

-

448

Universal Replicator

Universal Replicator for Mainframe

When the SVP detects a blocked path:

Mode 448 = ON: An error is assumed and the mirror is immediately suspended.

Mode 448 = OFF: If the path does not recover within a specified period of time, an error is assumed and the mirror is suspended.

Note: Mode 448 setting is available only when mode 449 is set to OFF.

OFF

-

449

Universal Replicator

Universal Replicator for Mainframe

This mode is used to enable and disable detection of communication failures between the MCU and RCU.

Mode 449 = ON: On the MCU side, checking read journal disruption from RCU is disabled, and monitoring read journal failures is disabled on the RCU side.

Mode 449 = OFF: Detecting communication failures between the MCU and RCU is enabled.

Notes:

1. This mode applies when disabling the detection of communication failures between the MCU and RCU in UR/URz configuration is required.
2. When this mode is set to ON, SOM 448 does not work.
3. This mode setting is not changed by microcode upgrade.
4. This mode is not effective for remote paths between an Initiator port on the MCU and a Target port on the RCU.
5. While a path from the RCU to MCU is disconnected, if the UR/URz pair remains in Suspending or Deleting status, recover it in accordance with the procedure in Recovery from UR/URz Failure in TROUBLE SHOOTING section of Maintenance Manual.

ON

MCU

454

Virtual Partition Manager

CLPR (function of Virtual Partition Manager) partitions the cache memory in the storage system into multiple virtual cache and assigns the partitioned virtual cache for each use. If a large amount of cache is required for a specific use, it can minimize the impact on other uses. The CLPR function works as follows depending on whether SOM 454 is set to ON or OFF.

Mode 454 = OFF: The amount of the entire destage processing is periodically determined by using the highest workload of all CLPRs (*a). (The larger the workload is, the larger the amount of the entire destage processing becomes.)

*a: (Write Pending capacity of CLPR#x of concerned MPB) ÷ (Cache capacity of CLPR#x of concerned MPB), x=0 to 31

CLPR whose value above is the highest of all CLPRs

Because the destage processing would be accelerated depending on CLPR with high workload, when the workload in a specific CLPR increases, the risk of host I/O halt would be reduced.

Therefore, set mode 454 to OFF in most cases.

Mode 454 = ON:

The amount of the entire destage processing is periodically determined by using the workload of the entire system (*b). (The larger the workload is, the larger the amount of the entire destage processing becomes.)

*b: (Write Pending capacity of the entire system of concerned MPB) ÷ (Cache capacity of the entire system of concerned MPB)

Caution: Because the destage processing would not be accelerated even if CLPR has high workload, when the workload in a specific CLPR increases, the risk of host I/O halt would be increased. Therefore, set mode 454 to ON only when a CLPR has constant high workload and the I/O performance in a CLPR with low workload has higher priority than host I/O halt in the CLPR with high workload.

Notes:

1. When this SOM is set to ON, even if there is an overloaded CLPR (CLPR with large Write Pending capacity), the amount of destage processing would not increase easily. Therefore TOV(MIH) may occur in the overloaded CLPR. Set this SOM to ON only when the overloaded state of a specific CLPR would not affect other CLPRs.

   When the UR function is used, if user volumes and journal volumes are defined in different CLPRs, when the CLPR to which the journal volumes are assigned overflows, the user volumes become inaccessible. Therefore it is recommended to set this SOM to OFF.

2. Because the destage processing will have a lower priority in the overloaded CLPR, the overloaded state of the overloaded CLPR is not removed, and TOV(MIH) may occur.

OFF

-

457

Universal Volume Manager

This SOM has two purposes: High-Speed LDEV Format for External Volumes, and Support for Mainframe Control Block Write GUI.

Mode 457 = ON:

1. High-Speed LDEV Format for External Volumes.

   The high-speed LDEV format for external volumes is available by SOM 457 to ON. When SOM 457 is ON, if you select an external volume group and perform an LDEV format, any write processing on the external logical units will be skipped. However, if the external LDEV is a mainframe volume, the write processing for mainframe control information only will be performed after the write skip.

2. Support for Mainframe Control Block Write GUI.

   Control Block Write of the external LDEVs in mainframe emulation is supported by Device Manager - Storage Navigator (GUI).

   - If the LDEV is not written with data “0” before performing the function, the LDEV format may fail.

   - After the format processing, make sure to set SOM 457 to OFF.

OFF

Both

459

ShadowImage

ShadowImage for Mainframe

When the S-VOL of an SI/SIz pair is an external volume, the transaction to change the status from SP-PEND to SPLIT is as follows:

Mode 459 = ON: When suspending an SI/SIz pair: The copy data is created in cache memory. When the write processing on the external storage completes and the data is fixed, the pair status will change to SPLIT.

Mode 459 = OFF: When suspending an SI/SIz pair: Once the copy data has been created in cache memory, the pair status will change to SPLIT. The external storage data is not fixed (current spec).

OFF

-

466

Universal Replicator

Universal Replicator for Mainframe

It is strongly recommended that the path between the primary and secondary storage systems have a minimum data transfer speed of 100 Mbps. If the data transfer speed falls to 10 Mbps or lower, UR operations cannot be properly processed. As a result, many retries occur and UR pairs might be suspended. This SOM is provided to ensure proper system operation for data transfer speeds of at least 10 Mbps.

Mode 466 = ON: Data transfer speeds of 10 Mbps and higher are supported. The JNL read is performed with 4-multiplexed read size of 256 KB.

Mode 466 = OFF (default): For conventional operations. Data transfer speeds of 100 Mbps and higher are supported. The JNL read is performed with 32-multiplexed read size of 1 MB by default.

Note: The data transfer speed can be changed using the Change JNL Group options.

OFF

-

467

ShadowImage

ShadowImage for Mainframe

Compatible FlashCopy® V2

Compatible FlashCopy® SE

Snapshot

Volume Migration

Universal Volume Manager

For the following features, the current copy processing slows down when the percentage of “dirty” data is 60% or higher, and it stops when the percentage is 75% or higher. Mode 467 is provided to prevent the percentage from exceeding 60%, so that the host performance is not affected.

• SI
• SIz
• FCv2, FCSE
• Snapshot
• UVM
• Volume Migration

Mode 467 = ON: Copy overload prevention. Copy processing stops when the percentage of “dirty” data reaches 60% or higher. When the percentage falls below 60%, copy processing restarts.

Mode 467 = OFF: Normal operation. The copy processing slows down if the dirty percentage is 60% or larger, and it stops if the dirty percentage is 75% or larger.

Caution: This mode must always be set to ON when using an external volume as the secondary volume of any of the applicable replication products.

Notes:

1. It takes longer to finish the copy processing because it stops for prioritizing the host I/O performance.
2. This mode supports background copy only. The processing to copy the pre-update data to the S-VOL, which occurs when overwriting data to uncopied slots of P-VOL in Split processing or reading or writing data to uncopied slots of S-VOL, is not supported.
3. Check the write pending rate of each CLPR per MP blade. Even though there is some free cache capacity in the entire system, if the write pending rate of an MP blade to which pairs* belong exceeds the threshold, the copy operation is stopped.

   *Applies to pairs of SI, SIz, FCv2, FCSE, Snapshot, and Volume Migration.

ON

-

471

Thin Image

Since the SIM-RCs generated when the Thin Image pool usage rate exceeds the threshold value can be resolved by users, these SIM-RCs are not reported to the maintenance personnel. This mode is used to report these SIM-RCs to maintenance personnel.

The SIM-RCs reported by setting the mode to ON are: 601xxx (Pool utilization threshold exceeded), 603000 (SM space warning).

Mode 471 = ON: These SIM-RCs are reported to maintenance personnel.

Mode 471 = OFF: These SIM-RCs are not reported to maintenance personnel.

Note: Set this mode to ON when it is required to inform maintenance personnel of these SIM-RCs.

OFF

-

474

Universal Replicator

Universal Replicator for Mainframe

UR initial copy performance can be improved by issuing a command from CCI/Business Continuity Manager (BCM) to execute a dedicated script consisting of UR initial copy (Nocopy), UR suspend, TC Sync initial copy, TC Sync delete, and UR resync.

Mode 474 = ON: For a suspended UR pair, a TC (Sync) pair can be created with the same P-VOL/S-VOL so that UR initial copy time can be reduced by using the dedicated script.

Mode 474 = OFF: For a suspended UR pair, a TC (Sync) pair cannot be created with the same P-VOL/S-VOL. For this, the dedicated script cannot be used.

If the P-VOL and S-VOL are both DP-VOLs, initial copy performance might not improve with SOM 474 set to ON. This is because with DP-VOLs, not all areas in a volume are allocated for UR; therefore not all areas in the P-VOL are copied to the S-VOL. With less than the full amount of data in the P-VOL being copied, the initial copy completes in a shorter time, which might not be improved with SOM 474.

Notes:

1. Set this mode for both primary and secondary storage systems.
2. When this mode is set to ON:

   - Execute all pair operations from CCI/BCM.

   - Use a dedicated script.

   - Initial copy operation is prioritized over update I/O. Therefore, the processing speed of the update I/O slows down.

3. If this mode is set to ON, the processing speed of update I/O slows down by about 15 μs per command, version downgrade is disabled, and Take Over is not available.
4. If this mode is not set to ON for both sides, the behavior is as follows:

   - OFF in primary and secondary storage systems: Normal UR initial copy performance.

   - ON in the primary storage system/OFF in the secondary storage system: TC Sync pair creation fails.

   - OFF in the primary storage system/ON in the secondary storage system: The update data is copied to the S-VOL synchronously.

5. While this mode is set to ON, make sure not to perform microcode downgrade to an unsupported version.
6. While this mode is set to ON, make sure not to perform the Take Over function.
7. This mode cannot be applied to a UR pair that is the second mirror in a URxUR multi-target configuration, URxUR cascade configuration, or 3DC multi-target or cascading configuration of three UR sites. If applied, TC pair creation is rejected with SSB=CBED output.
8. Before setting SOM 474 to ON, make sure that SOM 1091 is set to OFF. If SOM 1091 is set to ON, set it to OFF first, and then set SOM 474 to ON.

OFF

Both

506

Universal Replicator

Universal Replicator for Mainframe

This mode is used to enable Delta Resync with no host update I/O by copying only differential JNL instead of copying all data.

The UR Delta Resync configuration is required.

Mode 506 = ON:

• Without update I/O: Delta Resync is enabled.
• With update I/O: Delta Resync is enabled.

Mode 506 = OFF (default):

• Without update I/O: Total data copy of Delta Resync is performed.
• With update I/O: Delta Resync is enabled.

Note: Even when mode 506 is set to ON, the Delta Resync may fail and only the total data copy of the Delta Resync function is allowed if the necessary journal data does not exist on the primary storage system used for the Delta Resync operation.

OFF

Both

561

ShadowImage

Universal Volume Manager

Allows Quick Restore for external volumes with different Cache Mode settings.

Mode 561 = ON: Quick Restore for external volumes with different Cache Mode settings is prevented.

Mode 561 = OFF (default): Quick Restore for external volumes with different Cache Mode settings is allowed.

OFF

Both

589

Universal Volume Manager

When this mode is ON, the frequency of progress update of disconnection is changed.

Mode 589 = ON: For each external volume, progress is updated only when the progress rate is 100%.

Mode 589 = OFF (default): Progress is updated when the progress rate exceeds the previous level.

Notes:

1. Set this mode to ON when disconnecting an external volume while the specific host IO operation is online and its performance requirement is severe.
2. Whether the disconnecting status for each external volume is progressed or not cannot be confirmed on Device Manager - Storage Navigator (It indicates “-“until just before the completion and at the last it changes to 100%).

OFF

Both

689

TrueCopy

TrueCopy for Mainframe

global-active device

Allows you to slow the initial copy and resync operations when the write-pending rate on the RCU exceeds 60%.

Mode 689 = ON: The initial copy and resync copy operations are slowed down when the Write Pending rate on RCU exceeds 60%.

If the CLPR write pending rate where the initial copy target secondary volume belongs to is not over 60% but that of MP PCB where the S-VOL belongs to is over 60%, the initial copy operation is slowed down.

Mode 689 = OFF (default): The initial copy and resync copy operations are not slowed down when the Write Pending rate on RCU exceeds 60% (the same as before).

Notes:

1. This mode can be set online.
2. The micro-programs on both MCU and RCU must support this mode.
3. This mode should be set when requested by the user.
4. Setting this mode to ON is recommended when GAD is installed, as the performance degradation is more likely to occur due to active-active I/Os.
5. If the write-pending status remains at 60% or higher on the RCU for a long time, it takes extra time for the initial copy and resync copy to be completed due to the slower copy operations.
6. Do not set this mode if the primary or secondary system is connected to USP V/VM with microcode earlier than 60-02-xx-xx/xx. If this mode is applied and the write-pending rate reaches 60%, pair suspend might occur.
7. As this mode is enabled per storage system, in an environment where TC and GAD are used, this mode is applied to both program products. When GAD is installed in a storage system that already uses TC, TC initial copy might take longer time.

OFF

Both

690

Universal Replicator

Universal Replicator for Mainframe

This mode is used to prevent Read JNL or JNL Restore when the Write Pending rate on RCU exceeds 60% as follows:

• When CLPR of JNL-Volume exceeds 60%, Read JNL is prevented.
• When CLPR of Data (secondary)-Volume exceeds 60%, JNL Restore is prevented.

Mode 690 = ON: Read JNL or JNL Restore is prevented when the Write Pending rate on RCU exceeds 60%.

Mode 690 = OFF (default): Read JNL or JNL Restore is not prevented when the Write Pending rate on RCU exceeds 60% (the same as before).

Notes:

1. This mode can be set online.
2. This mode should be set per customer’s requests.
3. If the Write Pending status long keeps 60% or more on RCU, it takes extra time for the initial copy to be completed by making up for the prevented copy operation.
4. If the Write Pending status long keeps 60% or more on RCU, the pair status may become Suspend due to the JNL-Vol being full.
5. When USP/NSC is used on P-VOL side, the mode cannot be used. If the mode is set to ON, SSB=8E08 on P-VOL side and SSB=C8D1 on S-VOL side may frequently be output.

OFF

RCU

696

Open

This mode is available to enable or disable the QoS function.

Mode 696 = ON: QoS is enabled. (In accordance with the Share value set to SM, I/Os are scheduled. The Share value setting from RMLIB is accepted)

Mode 696 = OFF (default): QoS is disabled. (The Share value set to SM is cleared. I/O scheduling is stopped. The Share value setting from host is rejected.)

Note: Set this mode to ON when you want to enable the QoS function.

OFF

-

701

Universal Volume Manager

Issues the Read command at the logical unit discovery operation using UVM.

Mode 701 = ON: The Read command is issued at the logical unit discovery operation.

Mode 701 = OFF: The Read command is not issued at the logical unit discovery operation.

Notes:

1. When the external storage is USP/NSC and the Open LDEV Guard attribute (VMA) is defined on an external device, set the mode to ON.
2. As the VMA information is USP/NSC specific, this mode does not need to be ON when the external storage is other thanUSP/NSC.
3. When this mode is set to ON, it takes longer time to complete the logical unit discovery. The amount of time depends on external storages.
4. With this mode OFF, if searching for external devices with VMA ia set, the VMA information cannot be read.
5. When the mode is set to ON while the following conditions are met, the external volume is blocked:
   • An external volume to which Nondisruptive migration (NDM) attribute is set exists.
   • The external volume is reserved by the host
6. Set the mode to OFF when the following conditions are met:
   • An external volume to which Nondisruptive migration (NDM) attribute is set exists.

OFF

-

704

ShadowImage

Volume Migration

To reduce the chance of MIH, this mode can reduce the priority of ShadowImage, Volume Migration, or Resync copy internal IO requests so that host IO has a higher priority. This mode creates new work queues where these jobs can be assigned with a lower priority.

Mode 704 = ON: Copy processing requested is registered into a newly created queue so that the processing is scheduled with lower priority than host I/O.

Mode 704 = OFF: (Default) Copy processing requested is not registered into a newly created queue. Only the existing queue is used.

Notes:

1. Apply this mode when the load of host I/O to an ECC that uses ShadowImage or Volume Migration is high and the host I/O processing is delayed.
2. If the PDEV is highly loaded, the priority of Read/Write processing made by ShadowImage, Volume Migration, or Resync may become lower. As a consequence the copy speed may be slower.

OFF

-

721

Common

When a parity group is uninsulated or installed, the following operation is performed according to the setting of mode 721.

Mode 721 = ON: When a parity group is uninstalled or installed, the LED of the drive for uninstallation is not illuminated, and the instruction message for removing the drive does not appear. Also, the windows other than that of parity group, such as DKA or DKU, are unavailable to select.

Mode 721 = OFF (default): When a parity group is uninstalled or installed, the operation is as before: the LED of the drive is illuminated, and the drive must be unmounted and remounted.

Notes:

1. When the RAID level or emulation type is changed for the existing parity group, this mode should be applied only if the drive mounted position remains the same at the time of the parity group uninstallation or installation.
2. After the operation using this mode is completed, the mode must be set back to OFF; otherwise, the LED of the drive to be removed will not be illuminated at subsequent parity group uninstalling operations.

OFF

-

725

Universal Volume Manager

This mode determines the action that will be taken when the status of an external volume is Not Ready.

Mode 725 = ON: When Not Ready is returned, the external path is blocked and the path status can be automatically recovered (Not Ready blockade). Note that the two behaviors, automatic recovery and block, may be repeated.

When the status of a device is Not Ready blockade, Device Health Check is executed after 30 seconds.

Mode 725 = OFF (default): When Not Ready is returned three times in three minutes, the path is blocked and the path status cannot be automatically recovered (Response error blockade).

Notes:

1. Applying this SOM is prohibited when USP V/VM is used as an external storage system and its external volume is DP-VOL.
2. Applying this SOM is recommended when the above condition (1) is not met and SUN storage is used as an external storage.
3. Applying this SOM is recommended when the above condition (1) is not met and EMC CX series or Fujitsu Fibre CAT CX series is used as an external storage.
4. Applying this SOM is recommended if the above condition (1) is not met and a maintenance operation such as firmware update causing controller reboot is executed on the external storage side while a storage system other than Hitachi product is used as an external storage system.
5. While USP V/VM is used as an external storage system and its volume is DP-VOL, if some Pool-VOLs constituting the DP-VOL are blocked, external path blockade and recovery occurs repeatedly.
6. When a virtual volume mapped by UVM is set to pool-VOL and used as DP-VOL in local storage system, this SOM can be applied without problem.

OFF

-

729

Dynamic Provisioning

Data Retention Utility

To set the Protect attribute for the target DP-VOL using Data Retention Utility (DRU), when any write operation is requested to the area where the page allocation is not provided at a time when the DP Pool is full.

Mode 729 = ON: To set the Protect attribute for the target DP-VOL using DRU, when any write operation is requested to the area where the page allocation is not provided at a time when the DP pool is full. (Not to set in the case of Read request.)

Mode 729 = OFF (default): Not to set the Protect attribute for the target DP-VOL using DRU, when any write operation is requested to the area where the page allocation is not provided at a time when DP pool is full.

For details, contact customer support (see SOM729 & 803 sheet).

Notes:

1. This SOM is applied when:
   • The threshold of pool is high (for example, 95%) and the pool may be full.
   • File system is used.
   • Data Retention Utility is installed.
2. Since the Protect attribute is set for V-VOL, the Read operation cannot be allowed as well.
3. When Data Retention Utility is not installed, the desired effect is not achieved.
4. Protect attribute can be released from the Data Retention window of Device Manager - Storage Navigator after releasing the full status of the pool by adding a Pool-VOL.
5. With 80-02-0x or 83-01-2x and later, do not change the mode setting when the pool is full. Instead, use the virtual volume protection function to change the setting.
6. With 80-02-4x or 83-01-2x and later, when HMO63 or 73 is set to ON, the setting of the HMO takes precedence over the setting of SOM 729. SOM 729 acts as if it were turned OFF, even if it is actually turned ON.

OFF

-

733

ShadowImage

ShadowImage for Mainframe

Volume Migration

This mode enables to suspend Volume Migration or Quick Restore operation during LDEV-related maintenance.

Mode 733 = ON: Volume Migration or Quick Restore operation during LDEV-related maintenance is not suspended.

Mode 733 = OFF (default): Volume Migration or Quick Restore operation during LDEV-related maintenance is suspended.

Notes:

1. Note that behavior when the mode is set to ON and OFF is reversed between USP V/VM and VSP/HUS VM and later.
2. This mode should be applied to perform Volume Migration or Quick Restore during maintenance operation.
3. Set mode 733 to ON if you want to prioritize the Volume Migration or Quick Restore operation over maintenance activities. In this case, maintenance activities may fail when the Volume Migration or Quick Restore operation works during the maintenance activities.
4. An LDEV-related maintenance operation such as LDEV installation/removal may fail when Volume Migration or Quick Restore takes place.

OFF

-

734

Dynamic Provisioning

Dynamic Provisioning for Mainframe

OFF

-

741

Dynamic Provisioning

Dynamic Provisioning for Mainframe

The mode enables to switch over whether to report the following SIM for users to the service personnel:

SIM-RC 625000 (DP pool usage rate continues to exceed the threshold)

Mode 741 = ON: SIM is reported to the service personnel.

Mode 741 = OFF (default): SIM is not reported to the service personnel.

Notes:

1. This SOM is set to ON to have SIM for users reported to the service personnel:
   • For the system where SNMP and E-mail notification are not set.
   • If Device Manager - Storage Navigator is not periodically activated.
2. When SOM 734 is turned OFF, SIM-RC625000 is not reported; accordingly the SIM is not reported to the service personnel even though this mode is ON.

OFF

-

745

Universal Volume Manager

Enables to change the area where the information is obtained as the Characteristic1 item from SYMMETRIX.

Mode 745 = ON:

• The area where the information is obtained as the Characteristic1 item from SYMMETRIX is changed.
• When CheckPaths or Device Health Check (1/hour) is performed, the information of an already-mapped external volume is updated to the one after change.

Mode 745 = OFF (default):

• The area where the information is obtained as the Characteristic1 item from SYMMTRIX is set to the default.
• When CheckPaths or Device Health Check (1/hour) is performed, the information of an already-mapped external volume is updated to the default.

Notes:

1. This mode is applied when the EMC SYMMETRIX is connected using UVM.
2. Enable the setting of EMC SCSI Flag SC3 for the port of the EMC SYMMETRIX storage connected with the storage system and disable the setting of Flag SPC2. If the setting of EMC SCSI Flag SC3 is not enabled or the setting of Flag SPC2 is enabled, the effect of this mode may not be achieved.
3. If you want to enable this mode immediately after setting, perform Check Paths on each path one by one for all the external ports connected to the EMC SYMMETRIX storage. But, without doing Check Paths, the display of Characteristic1 can automatically be changed by the Device Health Check to be performed once an hour. If SSB=AD02 occurs and a path is blocked, perform Check Paths on this path again.

OFF

-

749

Dynamic Provisioning

Dynamic Provisioning for Mainframe

Dynamic Tiering

Dynamic Tiering for Mainframe

Thin Image

This mode disables the HDP Rebalance function and the HDT Tier relocation function which allow the drives of all ECC Groups in the pool to share the load.

Mode 749 = ON: The HDP Rebalance function and the HDT Tier relocation function are disabled.

Mode 749 = OFF (default): The HDP Rebalance function and the HDT Tier relocation function are enabled.

Notes:

1. This mode is applied when no change in performance characteristic is desired.
2. When a pool is newly installed, the load may be concentrated on the installed pool volumes.
3. When 0 data discarding is executed, load may be unbalanced among pool volumes.
4. Pool VOL deletion while the mode is set to ON fails. To delete pool VOLs, set the mode to OFF.

OFF

-

757

Common

Enables/disables output of in-band audit logs.

Mode 757 = ON: Output is disabled.

Mode 757 = OFF (default): Output is enabled.

Notes:

1. Mode 757 applies to the sites where outputting the In-band audit logs is not needed.
2. When this mode is set to ON:
   • There is no access to SM for the In-band audit logs, which can avoid the corresponding performance degradation.
   • SM is not used for the In-band audit logs.
3. If outputting the In-band audit log is desired, set this mode to OFF.

OFF

-

784

TrueCopy

TrueCopy for Mainframe

Global-active device

This mode can reduce the MIH watch time of RI/O for a TCz, TC, or GAD pair internally so that update I/Os can continue by using an alternate path without MIH or time-out occurrence in the environment where Mainframe host MIH is set to 15 seconds, or Open host time-out time is short (15 seconds or less). The mode is effective at initial pair creation or Resync operation for TCz, TC, or GAD. (Not effective by just setting this mode to ON.)

This mode is applied to TCz, TC, and GAD. The mode supports Fibre remote copy paths but not iSCSI.

Mode 784 = ON: The MIH time of RIO is internally reduced so that, even though a path failure occurs between storage systems in the environment where host MIH time is set to 15 seconds, update I/Os can be processed by using an alternate path promptly, lowering the possibility of host MIH occurrence.

Mode 784 = OFF (default): The operation is processed in accordance with the TCz, TC, or GAD specification.

Notes:

1. This mode is applied to the environment where Mainframe host MIH time is set to 15 seconds.
2. This mode is applied to the environment where OPEN host time-out time is set to 15 seconds or less.
3. This mode is applied to reduce RI/O MIH time to 5 seconds.
4. This function is available for all the TCz, TC, and GAD pairs on the storage system, unable to specify the pairs that are using this function or not.
5. To apply the mode to TCz, MCU and RCU must be USP V/VM or later models and micro-program must be the support version on both sides.
6. For a TCz, TC, or GAD pair with the mode effective (RI/O MIH time is 5 seconds), the setting of RI/O MIH time made at RCU registration (default is 15 seconds, which can be changed within range from 10 to 100 seconds) is invalid. However, RI/O MIH time displayed on Device Manager - Storage Navigator and CCI is not “5 seconds” but is what set at RI/O registration.
7. If a failure occurs on the switched path between storage systems, Mainframe host MIH or Open server time-out may occur.
8. If an MP to which the path between storage systems belongs is overloaded, switching to an alternate path delays and host MIH or time-out may occur.
9. If an RI/O retry occurs due to other factors than RI/O MIH (5 sec), such as a check condition report issued from RCU to MCU, the RI/O retry is performed on the same path instead of an alternate path. If a response delay to the RI/O occurs constantly on this path due to path failure or link delay, host MIH or time-out may occur due to response time accumulation for each RI/O retried within 5 seconds.
10. Even though the mode is set to ON, if Mainframe host MIH time or Open host time-out time is set to 10 seconds or less, host MIH or time-out may occur due to a path failure between storage systems.
11. Operation commands are not available for promptly switching to an alternate path.
12. The mode works for the pair for which initial pair creation or Resync operation is executed.
13. Micro-program downgrade to an unsupported version cannot be executed unless all the TCz, TC, and GAD pairs are suspended or deleted.
14. For operational specifications in each combination of MCU and RCU of TCz/TC, contact customer support (see SOM784 sheet).
15. For GAD pairs, the mode is effective if the microcode version supports GAD.
16. The mode does not support iSCSI paths between storage systems. When iSCSI is used for paths between storage systems, the time to switch to an alternate path cannot be reduced. For this, if a failure occurs on a path between storage systems in an environment where host time-out time is short, a time-out may occur on the host side. A time-out may also occur on the host side when a failure occurs on an iSCSI path between storage systems if storage system paths of Fibre and iSCSI coexist in an environment where host time-out time is short so that the configuration where storage system paths of Fibre and iSCSI coexist is not supported too.

OFF

Both

803

Dynamic Provisioning

Data Retention Utility

While a DP pool VOL is blocked, if a read or write I/O is issued to the blocked pool VOL, this mode can enable the Protect attribute of DRU for the target DP-VOL.

Mode 803 = ON: While a DP pool VOL is blocked, if a read or write I/O is issued to the blocked pool VOL, the DRU attribute is set to Protect.

Mode 803 = OFF (default): While a DP pool VOL is blocked, if a read or write I/O is issued to the blocked pool VOL, the DRU attribute is not set to Protect.

For more details, contact customer support (see SOM729 & 803 sheet).

Notes:

1. This mode is applied when:
   • A file system using DP pool VOLs is used.
   • Data Retention Utility is installed.
2. Because the DRU attribute is set to Protect for the V-VOL, a read I/O is also disabled.
3. If Data Retention Utility is not installed, the expected effect cannot be achieved.
4. The Protect attribute of DRU for the DP V-VOL can be released on the Data Retention window of Device Manager - Storage Navigator after recovering the blocked pool VOL.
5. With 83-01-2x and later, do not change the mode setting but use the virtual volume protection function when the pool volume is blocked to change the setting.

OFF

-

855

ShadowImage

ShadowImage for Mainframe

Volume Migration

By switching the mode to ON/OFF when ShadowImage is used with SOM 467 set to ON, copy processing is continued or stopped as follows.

Mode 855 = ON: When the amount of dirty data is within the range from 58% to 63%, the next copy processing is continued after the dirty data created in the previous copy is cleared to prevent the amount of dirty data from increasing (copy after destaging). If the amount of dirty data exceeds 63%, the copy processing is stopped.

Mode 855 = OFF (default): The copy processing is stopped when the amount of dirty data is over 60%.

For details, contact customer support (see SOM855 sheet).

Notes:

1. This mode is applied when all the following conditions are met
   • ShadowImage is used with SOM 467 set to ON.
   • Write pending rate of an MP blade that has LDEV ownership of the copy target is high
   • Usage rate of a parity group to which the copy target LDEV belongs is low.
   • ShadowImage copy progress is delayed.
2. This mode is available only when SOM 467 is set to ON.
3. If the workload of the copy target parity group is high, the copy processing may not be improved even if this mode is set to ON.

OFF

-

857

Common

This mode enables or disables to limit the cache allocation capacity per MP blade/unit to within the prescribed capacity* except for Cache Residency Manager.

Mode 857 = ON: The cache allocation capacity is limited to within the prescribed capacity*.

Mode 857 = OFF (default): The cache allocation capacity is not limited to within the prescribed capacity*.

*Prescribed capacity:

• VSP G1000, VSP G1500, VSP F1500: 256 GB
• VSP G800, VSP, HUS VM: 128 GB
• VSP G400, G600: 64 GB
• VSP G200: 16 GB

Notes:

1. This mode is applied to stabilize the performance by preventing paging of PM control information from occurring. For details, refer to the section of Virtual Partition Manager in the guideline.
2. The cache hit rate may decrease.
3. The cache allocation capacity per MPB/MPU is limited to within the prescribed capacity.

OFF

-

867

Dynamic Provisioning

Dynamic Tiering

All-page reclamation (discarding all mapping information between DP pool and DP volumes) is executed in DP-VOL LDEV format. This new method is enabled or disabled by setting the mode to ON or OFF.

Mode 867 = ON (default*): LDEV format of the DP-VOL is performed with page reclamation.

Mode 867 = OFF:LDEV format of the DP-VOL is performed with 0 data writing.

*The default is OFF for VSP, HUS VM, and VSP Gx00 models and VSP Fx00 models with firmware 83-03-xx and earlier.

Notes:

1. This mode is applied from factory shipment.
2. Do not change the setting of the mode during DP-VOL format.
3. If the setting of the mode is changed during DP-VOL format, the change is not reflected to the format of the DP-VOL being executed but the format continues in the same method.

ON

-

896

Dynamic Provisioning

Dynamic Provisioning for Mainframe

Dynamic Tiering

Dynamic Tiering for Mainframe

Thin Image

The mode enables or disables the background format function performed on an unformatted area of a DP/DT/TI pool.

For information regarding operating conditions, refer to Provisioning Guide of your storage system.

Mode 896 = ON (default): The background format function is enabled.

Mode 896 = OFF*: The background format function is disabled.

* For VSP Gx00 models and VSP Fx00 models, the operation of this mode is reversed: the background format function is enabled when this mode is OFF.

Notes:

1. This mode is applied when a customer requires the background format for a DP/DT/TI pool in the environment where new page allocation (in the case that system files are created from a host for newly created multiple DP-VOLs, for example) frequently occurs and the write performance degrades because of an increase in write pending rate.
2. When the background format function is enabled, because up to 42 MB/s of ECCG performance is used, local copy performance may degrade by about 10%. Therefore, confirm whether the 10% performance degradation is acceptable or not before enabling the function.
3. When a Dynamic Provisioning VOL on an external storage system, which is used as an external VOL, is used as a pool VOL, if the external pool on the external storage side becomes full due to the background format, the external VOL may be blocked.

   If the external pool capacity is smaller than the external VOL capacity (Dynamic Provisioning VOL of external storage system), do not enable the background format function.

4. If the background format function is disabled by changing the mode setting, the format progress is initialized and the entire area becomes unformatted.

OFF

-

897

Dynamic Tiering

Dynamic Tiering for Mainframe

By the combination of SOM 897 and 898 setting, the expansion width of Tier Range upper I/O value (IOPH) can be changed as follows.

Mode 897 = ON:

• SOM 898 is OFF: 110%+0IO
• SOM 898 is ON: 110%+2IO

Mode 897 = OFF (Default)

• SOM 898 is OFF: 110%+5IO (default)
• SOM 898 is ON: 110%+1IO

By setting the SOMs to ON to lower the upper limit for each tier, the gray zone between other tiers becomes narrow and the frequency of page allocation increases.

Notes:

1. Apply the mode when the upper tier usage is low and lower tier usage is high.
2. The mode must be used with SOM 898.
3. Narrowing the gray zone increases the number of pages to migrate between tiers per relocation.
4. When Tier1 is SSD while SOM 901 is set to ON, the effect of SOM 897 and 898 to the gray zone of Tier1 and Tier2 is disabled and the SOM 901 setting is enabled instead. In addition, the settings of SOM 897 and 898 are effective for Tier2 and Tier3.

For more details about the interactions between SOMs 897, 898, and 901, contact customer support (see SOM897_898_901 sheet).

OFF

-

898

Dynamic Tiering

Dynamic Tiering for Mainframe

By the combination of SOM 898 and 897 setting, the expansion width of Tier Range upper I/O value (IOPH) can be changed as follows.

Mode 898 = ON:

• SOM 897 is OFF: 110%+1IO
• SOM 897 is ON: 110%+2IO

Mode 898 = OFF (default):

• SOM 897 is OFF: 110%+5IO (default)
• SOM 897 is ON: 110%+0IO

By setting the SOMs to ON to lower the upper limit for each tier, the gray zone between other tiers becomes narrow and the frequency of page allocation increases.

Notes:

1. Apply the mode when the usage of upper tier is low and that of lower tier is high.
2. The mode must be used with SOM 897.
3. Narrowing the gray zone increases the number of pages to migrate between tiers per relocation.
4. When Tier1 is SSD while SOM 901 is set to ON, the effect of SOM 897 and 898 to the gray zone of Tier1 and Tier2 is disabled and the SOM 901 setting is enabled instead. In addition, the settings of SOM 897 and 898 are effective for Tier2 and Tier3.

For more details about the interactions between SOMs 897, 898, and 901, contact customer support (see SOM897_898_901 sheet).

OFF

-

899

In combination with the SOM 900 setting, this mode determines whether to execute and when to start the I/O synchronous copy change as follows.

Mode 899 = ON:

• SOM 900 is ON: I/O synchronous copy starts without retrying Volume Migration.
• SOM 900 is OFF: I/O synchronous copy starts when the threshold of Volume Migration retry is  exceeded. (Recommended)

Mode 899 = OFF (default):

• SOM 900 is ON: I/O synchronous copy starts when the number of retries reaches half of the threshold of Volume Migration retry.
• SOM 900 is OFF: Volume Migration is retired and I/O synchronous copy is not executed.

Notes:

1. This mode is applied when improvement of Volume Migration success rate is desired under the condition that there are many updates to a migration source volume of Volume Migration.
2. During I/O synchronous copy, host I/O performance degrades.

OFF

-

900

Volume Migration

In combination with SOM 899 setting, this mode determines whether to execute and when to start the I/O synchronous copy change as follows.

Mode 900 = ON:

• SOM 899 is ON: I/O synchronous copy starts without retrying Volume Migration.
• SOM 899 is OFF: I/O synchronous copy starts when the number of retries reaches half of the threshold of Volume Migration retry.

Mode 900 = OFF (default):

• SOM 899 is ON: I/O synchronous copy starts when the threshold of Volume Migration retry is exceeded. (Recommended)
• SOM 899 is OFF: Volume Migration is retired and I/O synchronous copy is not executed.

Notes:

1. This mode is applied when improvement of Volume Migration success rate is desired under the condition that there are many updates to a migration source volume of Volume Migration.
2. During I/O synchronous copy, host I/O performance degrades.

OFF

-

901

Dynamic Tiering

Dynamic Tiering for Mainframe

By setting the mode to ON or OFF, the page allocation method of Tier Level ALL when the drive type of tier1 is SSD changes as follows.

Mode 901 = ON: For tier1 (drive type is SSD), pages are allocated until the capacity reaches the limit. Without consideration of exceeding performance limitation, allocation is done from highly loaded pages until reaching the capacity limit

When the capacity of the tier1 reaches the threshold value, the minimum value of the tier range is set to the starting value of the lower IOPH zone, and the maximum value of the lower tier range is set to the boundary value.

Mode 901 = OFF (default): For tier1 (drive type is SSD), page allocation is performed based on performance potential limitation. With consideration of exceeding performance limitation, allocation is done from highly loaded pages but at the point when the performance limitation is reached, pages are not allocated any more even there is free space.

When the capacity of the tier1 reaches the threshold value, the minimum value of the tier range is set to the boundary value, and the maximum value of the lower tier range is set to a value of boundary value × 110% + 5 [IOPH].

Notes:

1. This mode is applied when pages with the maximum capacity need to be allocated to tier1 (drive type is SSD) with Dynamic Tiering or Dynamic Tiering for Mainframe.
2. When Tier1 is SSD while SOM 901 is set to ON, the effect of SOM 897 and 898 to the gray zone of Tier1 and Tier2 is disabled and the SOM 901 setting is enabled instead. In addition, the settings of SOM 897 and 898 are effective for Tier2 and Tier3.

3. The following is recommended when applying SOM 901.

   actual I/O value (total number of I/Os of all tiering policies) < performance potential value of Tier 1* × 0.6

   * The performance potential value of Tier1 displayed on Monitor information by using Dx-ray.

For more details about the interactions between SOMs 897, 898, and 901, contact customer support (see SOM897_898_901 sheet).

OFF

-

904

Dynamic Tiering

Dynamic Tiering for Mainframe

By setting the mode to ON or OFF, the number of pages to be migrated per unit time at tier relocation is changed.

Mode 904 = ON: The number of pages to be migrated at tier relocation is set to up to one page per second.

Mode 904 = OFF (default):No restriction on the number of pages to be migrated at tier relocation (existing specification).

Notes:

1. This mode is applied when:
   • Dynamic Tiering for Mainframe is used (including multi-platform configuration).
   • The requirement for response time is severe.
2. The number of pages to be migrated per unit time at tier relocation decreases.

OFF

-

908

Universal Replicator

Universal Replicator for Mainframe

This mode can change CM capacity allocated to MPBs with different workloads.

Mode 908 = ON: The difference in CM allocation capacity among MPBs with different workload is large.

Mode 908 = OFF (default): The difference in CM allocation capacity among MPBs with different workload is small (existing operation) .

Notes:

1. If a CLPR is used by only some MPBs among all the installed MPBs, set the mode to ON for the CLPR to increase CM capacity allocated to the MPBs that use the CLPR.

   Example:

   (a) A CLPR only for UR JNLG.

   (b) A configuration where MPBs and CLPRs are separately used for Open and Mainframe systems.

2. Since CM capacity allocated to MPBs with low load is small, the performance is affected by a sudden increase in load.
3. SOM 908 cannot be used with SOM 933. When SOM 933 is set to ON, the function of SOM 908 is canceled even though SOM 908 is ON.
4. This mode is effective for a CLPR. Therefore, when setting the mode to ON/OFF, select target "LPRXX (XX=00 to 31)". For example, even when CLPR0 is defined (any of CLPR1 to 31 are not defined), select “LPR00” first and then set the mode to ON/OFF.

OFF

Both

930

Dynamic Provisioning

Dynamic Tiering

ShadowImage

When the mode is set to ON, all of the zero data page reclamation operations in processing are stopped. (Also the zero data page reclamation cannot be started.)

* Zero data page reclamation by WriteSame and UNMAP functions, and IO synchronous page reclamation are not disabled.

Mode 930 = ON: All of the zero data page reclamation operations in processing are stopped at once. (Also the zero data reclamation cannot be newly started.)

Mode 930 = OFF (default): The zero data page reclamation is performed.

For details about interactions with SOM 755, contact customer support (see SOM930 sheet).

Notes:

1. This mode is applied when stopping or disabling zero data page reclamation by user request is required.
2. When the mode is set to ON, the zero data page reclamation does not work at all.

   * Zero data page reclamation by Write Same and UNMAP, and IO synchronous page reclamation can work.

3. When downgrading micro-program to a version that does not support the mode while the mode is set to ON, set the mode to OFF after the downgrade.

   * Because the zero data page reclamation does not work at all while the mode is set to ON.

4. The mode is related to SOM 755.

OFF

-

937

Dynamic Provisioning

Dynamic Provisioning for Mainframe

Dynamic Tiering

Dynamic Tiering for Mainframe

By setting the mode to ON, HDT monitoring data is collected even if the pool is a DP pool.

Mode 937 = ON: HDT monitoring data is collected even if the pool is a DP pool.

Only Manual execution mode and Period mode are supported.

Mode 937 = OFF (default): HDT monitoring data is not collected if the pool is a DP pool

Notes:

1. This mode is applied when HDT monitoring data collection is required in DP environment.
2. When HDT is already used, do not set the mode to ON.
3. For HDT monitoring data collection, shared memory for HDT must be installed. For details, contact customer support (see SOM937 sheet).
4. If monitoring data collection is performed without shared memory for HDT installed, an error is reported and the monitoring data collection fails.
5. Before removing the shared memory for HDT, set the mode to OFF and wait for 30 minutes.
6. Tier relocation with monitoring data collected when the mode is set to ON is disabled.
7. When DP is converted into HDT (after purchase of software license), the collected monitoring data is discarded.
8. Before downgrading the micro-program to an unsupported version, set SOM 937 to OFF and wait for at least 30 minutes.

OFF

-

972

Common

By setting the mode, THP Page Size in Inquiry Page E3h is changed. THP Page Size varies depending on the combination of SOM 972 and 973 settings. For details, contact customer support (see SOM972_973 sheet).

Notes:

1. This mode is applied when a delay in host I/O response due to reclamation processing occurs in a customer environment.
2. Reclamation processing is delayed.
3. The mode is to prioritize host I/O response over reclamation processing in VxVM environment, so that the time required for reclamation processing may increase when the mode is set to ON.

For details about the interaction between this mode and SOM 1069, contact customer support (see SOM1069 sheet).

OFF

-

973

Common

By setting the mode, THP Page Size in Inquiry Page E3h is changed. THP Page Size varies depending on the combination of SOM972 and 973 settings. For details, contact customer support (see SOM972_973 sheet).

Notes:

1. This mode is applied when a delay in host I/O response due to reclamation processing occurs in a customer environment.
2. When the mode is set to ON, reclamation processing is delayed.
3. The mode is to prioritize host I/O response over reclamation processing in VxVM environment, so that the time required for reclamation processing may increase when the mode is set to ON.

For details about the interaction between this mode and SOM 1069, contact customer support (see SOM1069 sheet).

OFF

-

1021

Universal Volume Manager

The mode can enable or disable the auto-recovery for external volumes of an EMC storage system.

Mode 0121 = ON: An external volume that is blocked due to Not Ready status can be recovered automatically regardless of the type of external storage system.

Mode 1021 = OFF (default): An external volume that is blocked due to Not Ready status might not be recovered automatically depending on the type of external storage system.

Notes:

1. This mode is applied when the auto-recovery of external volumes that are blocked due to Not Ready status is desired in UVM connection using an ECM storage system as an external storage system.
2. When the mode is set to ON and the connected external storage system is not in stable status (such as failure and recovery from failure), a blockage due to Not Ready status and auto-recovery might occur repeatedly.

OFF

-

1043

Universal Replicator

Universal Replicator for Mainframe

This mode disables journal copy.

Mode 1043 = ON: When one of the following conditions is met at the UR secondary site, the journal copy is disabled.

(a) Write Pending rate of MP blade for which journal ownership is defined is 25% or higher.

(b) Initiator operating rate of MP blade for which journal ownership is defined is 40% or higher.

Mode 1043 = OFF (default): The journal copy is not disabled.

Notes:

1. This mode applies when (a) and (b), or (a) and (c) are met.

   (a) Usage of journal volume in the UR secondary site is high.

   (b) The configuration contains multiple primary and secondary sites.

   (c) A consistency group configuration contains both open and mainframe hosts.

2. If SOM 690 is set to ON and the Write Pending rate is 60% or higher, the journal copy is disabled regardless of the setting of this mode.
3. When the host write speed is faster than the JNL copy speed, the usage rate of the master journal increases.
4. This mode is effective within the range of each CLPR. Therefore, an operation target LPRxx (xx= 00 to 31) needs to be selected before setting this mode to ON/OFF.

   For example, when setting this mode only to CLPR0 (even though the mode is not set to CLPR 1 to 31), select "LPR00" and then set this mode to ON/OFF. If "System" is selected and then this mode is set to ON, this mode is not effective for any of the CLPRs.

OFF

Both

1067

Universal Replicator

Universal Replicator for Mainframe

This mode is used to enable microcode downgrade to a version that does not support URxUR (including delta).

Mode 1067 = ON: Even when a UR pair has been registered, downgrading the microcode to a version that does not support URxUR (including delta) is allowed.

Mode 1067 = OFF (default): If any UR pair has been registered, downgrading the microcode to a version that does not support URxUR (including delta) is not allowed.

Notes:

1. This mode is applied to enable microcode downgrade to a version that does not support URxUR (including delta) if the configuration where any UR pair has been registered is not URxUR (including delta).
2. Setting the mode to ON allows microcode downgrade at sites where only 1 mirror is used in URxUR multi-target configuration without delta resync and cascade configuration (L or R site in multi-target, and P or R site in cascade), but the following phenomena occur after microcode downgrade. Make sure that the target storage system does not contain pairs of URxUR configuration.

   Phenomena:

   1. When the microcode is downgraded at S site (local or remote) in multi-target configuration, the pair between P site and the target S site cannot be resynchronized.
   2. When the pair between I site and R site in cascade configuration is resynchronized, the pair status cannot change from COPY to PAIR.
   3. When the microcode is downgraded at R site in cascade configuration, the pair between I site and R site cannot be resynchronized.

OFF

Both

1069

Common

By setting the mode, the INQUIRY Page E3h field is changed. The field varies depending on the combination of SOMs 972, 973, and 1069. For details, contact customer support (see SOM1069 sheet).

Notes:

1. This mode is applied when the page problem occurs in an environment where Symantec ASL 6.0.5 or higher is used and SOM 972 and/or 973 is set to ON.
2. When the mode is set to ON, reclamation processing is delayed.
3. The priority of setting when SOMs are set at the same time is SOM 1069, 972, and then 973. The setting of higher priority SOM is enabled.

OFF

-

1070

Global-active device

The mode changes the processing for a group operation with GAD consistency group (CTG).

Mode 1070 = ON: The status change of all pairs in a consistency group. is performed for 50 msec.

Mode 1070 = OFF (default): The status change of all pairs in a consistency group is performed for 1 msec.

Notes:

1. This mode is applied when reducing the time to complete status change of all pairs in a consistency group at a group operation (suspension and resync operation) with the GAD CTG function. In a system configuration where host I/O performance is prioritized, do not use the mode because setting the mode may affect the host I/O performance.
2. The MP usage rate increases during status change of all pairs in a consistency group. For details about approximate percentage increase in MP usage rate, contact customer support (see SOM1070 sheet).

OFF

Both

1079

Dynamic Provisioning

Dynamic Tiering

This mode is set not to run the Proprietary ANCHOR command during microcode downgrade from a version that supports the Proprietary ANCHOR command to a version that does not support the command.

Mode 1079 = ON: The Proprietary ANCHOR command is unavailable.

Mode 1079 = OFF (default): The Proprietary ANCHOR command is available.

Notes:

1. This mode is applied when downgrading the microcode from a version that supports the Proprietary ANCHOR command to a version that does not support the command.
2. Whether the Proprietary ANCHOR command can be run or not varies depending on the setting combination of SOM 1079 and HMO 97 as follows:
   1. SOM 1097 setting ON/HMO 97 setting ON --> Proprietary ANCHOR command Unavailable
   2. SOM 1097 setting ON/HMO 97 setting OFF --> Proprietary ANCHOR command Unavailable
   3. SOM 1097 setting OFF/HMO 97 setting ON --> Proprietary ANCHOR command Available
   4. SOM 1097 setting OFF/HMO 97 setting OFF --> Proprietary ANCHOR command Unavailable

OFF

-

1080

Global-active device

Universal Volume Manager

The mode is intended for a case that multiple external connection paths are connected to a Target port on an external system with a quorum disk and there is a path whose performance degrades. For such a case, the mode can eliminate impacts on commands run for other external devices that share the Target port with the quorum disk on the external system by setting the time to run a reset command for the Target port to be the same (15 seconds) as that to run other commands for the other external devices.

Mode 1080 = ON: The time to run the reset command for the quorum disk on the external system is 15 seconds to eliminate the impacts on commands run for the other external devices that share the Target port with the quorum disk on the external system.

If a response to ABTS is delayed for 12 seconds or longer, the quorum disk may be blocked.

Mode 1080 = OFF (default): The time to run a reset command for the quorum disk when performance of a path degrades is 3 seconds so that a retry is performed by an alternate path to avoid quorum disk blockage.

Notes:

1. This mode is applied if avoiding impacts on commands for other external devices sharing a Target port on an external system side with a quorum disk is prioritized over preventing quorum disk blockage when a response to ABTS is delayed.

   The delay is caused due to path performance degradation in a configuration where the Target port is shared between external devices and the quorum disk.

2. When connection performance degradation occurs, the quorum disk blockage is more likely to occur.

OFF

-

1083

Dynamic Provisioning

Universal Volume Manager

The mode enables or disables DP-VOL deletion while an external volume associated with the DP-VOL with data direct mapping attribute is not disconnected.

Mode 1083 = ON: DP-VOL deletion is enabled.

Mode 1083 = OFF (default): DP-VOL deletion is disabled.

Notes:

1. This mode is applied when the following conditions are met.
   • A DP-VOL with data direct mapping attribute is deleted.
   • The data of external volume with data direct mapping attribute associated with a deletion target DP-VOL with data direct mapping attribute will not be used again.
2. When SOM 1083 is set to ON, the data of external volumes cannot be guaranteed.
3. When DP-VOL deletion is performed without disconnecting an external volume, the data of the external volume cannot be guaranteed.

OFF

-

1086

Dynamic Provisioning

Dynamic Provisioning for Mainframe

Universal Volume Manager

This mode enables or disables the performance improvement for Dynamic Provisioning volumes that are Universal Volume Manager volumes used as pool volumes.

Mode 1086 = ON (default): The performance improvement is enabled.

Mode 1086 = OFF: The performance improvement is disabled.

Notes:

1. This mode is applied when the IOPS performance of an external storage system is higher than 80k x the number of installed MPBs, which is the value of IOPS that an entire local storage system sends to an external storage system.
2. When it is required to set the mode to OFF, if IOPS sent from the local storage system to the external storage system is higher than 80k x the number of installed MPBs, reduce the IOPS to lower than 80k x the number of installed MPBs, and then set the mode to OFF. (Otherwise CWP increases and cache is overloaded.)

OFF

-

1093

Dynamic Provisioning

Dynamic Tiering

Thin Image

This mode is used to disable background unmap during microcode downgrade from a version that supports pool reduction rate correction to a version that does not support the function.

Mode 1093 = ON: Background unmap cannot work.

Mode 1093 = OFF (default): Background unmap can work.

Note: This mode is applied when downgrading microcode from a version that supports pool reduction rate correction to a version that does not support the function is disabled.

OFF

-

1097

Common

This mode disables the warning LED to blink when specific SIMs are reported.

Mode 1097 = ON: When SIM=452XXX, 462XXX, 3077XY, 4100XX, or 410100 is reported, the warning LED does not blink.

Mode 1097 = OFF (default): When SIM=452XXX, 462XXX, 3077XY, 4100XX, or 410100 is reported, the warning LED blinks.

Note: The mode disables the warning LED to blink when specific SIMs are reported.

OFF

-

1106

Dynamic Provisioning

Dynamic Provisioning for Mainframe

Dynamic Tiering

Dynamic Tiering for Mainframe

This mode is used to monitor the page usage rate of parity groups defined to a pool, and perform rebalance to balance the usage rate if the rate differs significantly among parity groups.

Mode 1106 = ON: The usage rate is checked once a day and the rebalance works if the rate is not even.

Mode 1106 = OFF (default): The rebalance does not work even when the usage rate is not balanced.

The pool usage rate is determined as unbalanced when there is 25% or more difference between the usage rate of each parity group in the pool and the average.

Note: For HDT pools (including those with active flash attribute), the average of parity group usage rates is calculated per tier.

Examples:

1. In an HDP pool, if the usage rates of PG1, PG2, and PG3 are 50%, 40%, and 30% respectively, it is not determined as unbalanced.

   Because the average parity group usage rate is (50%＋40%＋30%) / 3 ＝40% and the difference in the rate between each parity group and the average is 10% at the maximum.

2. In an HDP pool, if the usage rates of PG1, PG2, and PG3 are 80%, 40%, and 30% respectively, it is determined as unbalanced.

   Because the average parity group usage rate is (80%＋40%＋30%) / 3 ＝50% and the difference in the rate between each parity group and the average is 30% at the maximum.

3. In an HDT pool, if the usage rates of PG1, PG2, and PG3 are 80% (SSD), 40% (SAS15K) and 30% (SAS15K), it is not determined as unbalanced, because:

   - the average parity group usage rate of Tier1 is (80%) / 1 ＝80% and the difference in the rate between the parity group and the average is 0%.

   - the average parity group usage rate of Tier2 is (40%＋30%) / 2 ＝35% and the difference in the rate between the parity group and the average is 5% at the maximum.

Note: This mode is applied when balancing the usage rate is required at a customer site where the usage rate is not even.

OFF

-

1115

Deduplication and Compression

When this mode is set to ON, data is initialized without using metadata at LDEV format for a virtual volume with Capacity Saving enabled.

Mode 1115 = ON: When LDEV format is performed for a virtual volume whose capacity saving setting is Compression, the data is initialized without using the metadata.

Mode 1115 = OFF (default): When LDEV format is performed for a virtual volume whose capacity saving setting is Compression, normal formatting is performed, but if one of the following conditions is met, the data is initialized without using metadata.

• There is a pinned slot.
• The capacity saving status is “Failed”.
• The virtual volume is blocked (Normal restore cannot be performed).

Notes:

1. This mode is applied to recover a blocked pool volume in a pool to which a virtual volume whose capacity saving setting is Compression belongs.

   For the information of setting timing, refer to the procedure for blocked pool volume recovery in the Maintenance Manual.

2. The processing time increases with increase in pool capacity.

   Estimate of processing time:

   Processing time (minutes) = ceiling(pool capacity (TB)/40) + 5

   The processing finishes early if there is less capacity of allocated pages.

3. Do not change the mode setting during LDEV format for a virtual volume whose capacity saving setting is Compression. If the setting is changed, the processing cannot be performed correctly and may end abnormally depending on the timing.
4. The mode is effective only for LDEV format for a virtual volume whose capacity saving setting is Compression, so that there is no side effect in relation to user data, but the processing may take more time than that when the mode is set to OFF depending on the pool capacity. Therefore, basically do not use the mode for cases other than pool volume blockage recovery.

OFF

-

1118

Open

This mode is used to disable the ENC reuse function.

Mode 1118 = ON: When a failure occurs in the Expander chip mounted on a controller board (CTLS, CTLSE) or an ENC board, the reuse function does not work but SIM=CF12XX is reported and the ENC is blocked.

Mode 1118 = OFF (default): When a failure occurs in the Expander chip mounted on a controller board (CTLS, CTLSE) or an ENC board, the reuse function works.

If the ENC is reusable, SIM=CF12XX and then CF14XX are reported, and the ENC is reused.

If the ENC is not reusable, SIM=CF12XX is reported, and the ENC is blocked.

Note: The ENC reuse function is enabled as default. This mode is applied when you want to disable the ENC reuse function.

OFF

-

1119

Deduplication and Compression

This mode is used to downgrade the microcode as follows while capacity saving is enabled:

• VSP G1000, VSP G1500, VSP F1500: From 80-05-05-00/00 or later to 80-05-01-00/00 or later
• VSP Gx00 models, VSP Fx00 models: From 83-04-03-x0/00 or later to 83-04-01-x0/00 or 83-04-02-x0/00

New control information is added with 80-05-05/83-04-03 for the inflow control processing when capacity saving is enabled. However, it must be guaranteed that the area is not used when the microcode version is 80-05-01/83-04-01 or later. This system option mode disables the control information added with 80-05-21/83-04-21 when capacity saving is enabled to enable microcode downgrade.

Mode 1119 = ON: The control information is not used when capacity saving is enabled.

Mode 1119 = OFF: The control information is used when capacity saving is enabled.

Notes:

1. Set this mode to ON when the microcode downgrade described above is performed, even if capacity saving is not currently in use but has been used before.
2. After the microcode downgrade is complete, make sure to set the mode to OFF.
3. The mode is effective for the entire storage system.
4. The write performance might degrade when this mode is ON.

OFF

-