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, call the HSSC (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 83-01-21-x0/00 and later, the Virtual Volume Protection (VVP) function is supported. VVP can be enabled/disabled for each pool. With SOM 729 disabled, VVP is also disabled by default, but you can enable VVP for each pool as needed. With SOM 729 enabled, VVP is also enabled automatically (by default) when you create a new pool. Caution: A pool is NOT protected by ANY FUNCTION if you deliberately turn VVP for the pool from ON (default) to OFF, even with SOM 729 enabled.
6. With or 83-01-21-x0/00 and later, when HMO 63 or 73 is set to ON, the setting of the HMO is prioritized over the SOM 729 setting so that the behavior remains as that of setting the mode to OFF even when the SOM is set to ON.

OFF

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734

Dynamic Provisioning

OFF

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741

Dynamic Provisioning

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

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749

Dynamic Provisioning

Dynamic Tiering

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

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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, call the HSSC (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 83-01-21-x0/00 and later, the Virtual Volume Protection (VVP) function is supported. VVP can be enabled/disabled for each pool. With SOM 803 disabled, VVP is also disabled by default, but you can enable VVP for each pool as needed. With SOM 803 enabled, VVP is also enabled automatically (by default) when you create a new pool. Caution: A pool is NOT protected by ANY FUNCTION if you deliberately turn VVP for the pool from ON (default) to OFF, even with SOM 803 enabled.

OFF

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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 Tiering

Thin Image

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

For information regarding operating conditions, see the Provisioning Guide.

Mode 896 = ON: The background format function is disabled.

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

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.
5. The background format for FMC drives is not disabled. When FMC drives are used, use SOM 1093.

OFF

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897

Dynamic Tiering

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, call the HSSC (see SOM897_898_901 sheet).

OFF

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898

Dynamic Tiering

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, call the HSSC (see SOM897_898_901 sheet).

OFF

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901

Dynamic Tiering

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.
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, call the HSSC (see SOM897_898_901 sheet).

OFF

-

904

Dynamic Tiering

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 the requirement for response time is severe.
2. The number of pages to be migrated per unit time at tier relocation decreases.

OFF

-

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, call the HSSC (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 Tiering

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, call the HSSC (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

-

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

-

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

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

-

1106

Dynamic Provisioning

Dynamic Tiering

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) = ceil(pool capacity (TB)/40) + 5

   ceil: The value enclosed in ceil( ) must be rounded up to the nearest whole number.

   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

-

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 (default): 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

-