Auxiliary-write cache IOA (FC 5580, 5581)(CCIN 5708)

Learn about the auxiliary-write cache IOA adapter and the PCI-X Ultra4 RAID disk-controller adapters used with it.

Feature 5580 includes a 2780 PCI-X Ultra4 RAID disk-controller adapter, a CCIN 5708 auxiliary-write cache IOA adapter, and the required connection cable. Feature 5581 includes a 2757 PCI-X Ultra RAID disk-controller adapter, a CCIN 5708 auxiliary-write cache IOA adapter, and the required connection cable.

Figure 1. 5708, auxiliary-write cache IOA

A physical cable connection is required between the 5708 adapter and SCSI port 4 of a 2780 or 2757 adapter. Both the 5708 adapter and the disk-controller adapter it is connected to must be installed in the same physical system unit or expansion unit, and must be installed in the same partition.

The 5708 adapter has 757 MB of auxiliary maximum compressed write cache. The adapter mirrors the write cache of the disk-controller adapter that it is connected to. Protection of data is enhanced by having two copies of the write cache stored on separate adapters. If a failure occurs to the write cache of the disk-controller, the 5708 adapter provides a backup copy during the recovery of the failed IOA.

Considerations for installing or converting to feature 5580 or 5581

Attention: Converting your adapters to feature 5580 or 5581 will require extensive planning. If the planning is not done correctly, the result could be an extended server outage, loss of data, or both. You might need to do a full system restore.

Read the following questions in relation to your system:

Are you converting from feature 2780 to feature 5580?
Are you converting from feature 2757 to feature 5581?
Are you replacing any other existing storage adapters with features 5580 and 5581?
Is your server partitioned (LPAR) ?

If the answer to any of these questions is yes, or you are unsure of the answers, contact your authorized service provider for planning and deployment services.

For planning information and examples of deployment for features 5580 and 5581, see Planning for Disk Storage Availability with Cache Solutions

5708 adapter specifications

Item	Description
Adapter FRU number	39J0686
Battery FRU number	97P4846
Cable FRU number	39J1702
Cables	Specific Storage Adapter to Auxiliary Storage Adapter SCSI cable is necessary and is provided with each feature or conversion.
I/O bus architecture	PCI 2.2 power/bus compliant
Unit description	Long, 64 bit, 133 MHz, 3.3 V edge connector, single-slot PCI-X 2.0 compliant Compatible down to 32 bit, 33 MHz PCI adapter slots
Operating system or partition requirements	Supported in the i5/OS^® operating systems or partitions only, versions V5R2, V5R3, and later.
Maximum number	For system-specific adapter placement, see PCI placement in the system unit or expansion unit.
Partition information	If you are placing the feature in the primary partition or any non-partitioned system, the auxiliary cache IOA for the load source (LS) adapter must be in the same enclosure as the LS IOA. If you are placing the feature in the secondary partition on any system, the auxiliary cache IOA for the LS adapter must be under the LS IOP.
Related information	This feature must be placed in attached expansion units. The 5708 adapter cannot be placed in the model 520, 550, or 570 system units. The disk controller adapter and the auxiliary-write cache adapter each require one PCI slot. Both adapters must be installed in the same enclosure. The adapters are connected by a SCSI cable (provided). The operating system identifies the 5708 adapter as a storage controller with no devices attached. The 5708 adapter is not supported in an environment without an IOP. Types 2780 and 2757 will not appear on ordering, shipping, or inventory documentation when received as part of these features.

Installing the adapters

To install the adapters, see PCI adapters, then return here for instruction on installing the SCSI cable.

Installing the SCSI cable

The disk controller adapter and the auxiliary-write cache adapter are connected by a SCSI cable.

Attention: Do not install or remove the adapter cable if the adapters have the power on. Use the service procedures to turn off the power to the adapter slots or shut down the system or partition in which the adapters are placed.

To install the SCSI cable, do the following:

Attach the SCSI cable to SCSI bus port 3 (fourth physical port) of the disk controller adapter.
Attach the cable to the SCSI port on the auxiliary-write cache adapter.

Note:

Attaching the cable to the disk controller reduces the number of SCSI buses that support disk drives from four to three.
Reducing the number of SCSI buses might also reduce the number of disk drives supported by the disk controller, depending on the system unit or expansion drawer in which the disk controller is installed.
No disk drives are driven by the auxiliary-write cache adapter. This adapter protects against extended outage caused by loss of write cache, but does not protect against a disk controller failure.