"Write Cache Active" Becomes False After Firmware Upgrade to 7.xx

Asset ID:	1-72-1906072.1
Update Date:	2014-08-12
Keywords:

Solution Type Problem Resolution Sure

Solution 1906072.1 : "Write Cache Active" Becomes False After Firmware Upgrade to 7.xx

Applies to:

Sun Storage 6580 Array - Version All Versions and later
Sun Storage 6540 Array - Version All Versions and later
Sun Storage 6140 Array - Version All Versions and later
Sun Storage 6180 Array - Version All Versions and later
Sun Storage 6780 Array - Version All Versions and later
Information in this document applies to any platform.

Symptoms

Write Cache gets disabled for all volumes when the array controller firmware is upgraded from any 07.xx firmware revision to 07.60.18.10 or later revisions up to 07.60.56.10.
Note that this symptom can also be seen while upgrading from 06.xx to 07.xx, because 06.xx to 07.xx upgrade utility takes to 07.15.xx.xx firmware first and then to later revisions.

This issue can be verified from file "storageArrayProfile.txt" under CAM supportdata collected after the firmware upgrade. Refer to <Document 1002514.1> Collecting Sun Storage Common Array Manager Support Data for Arrays for steps to collect array supportdata.

Volume name: xxx
      Volume handle: 1
      Volume WWN: yyyy       Status: Optimal
      Preferred owner: Tray.00.Controller.B
      Current owner: Tray.00.Controller.B
      Capacity: 10 GB (10,737,418,240 Bytes)
      Raid level: RAID 5
      Block Size: 512
      Segment size: 64 KB
      Reconstruction priority: 1 (High)
      Associated volume group: 1
      Read cache enabled: true
      Read cache active: true
      Write cache enabled: true
      Write cache active: false    <---
      Write cache without batteries: false
      Write cache with mirroring enabled: true
      Write cache with mirroring active: false <---
      Flush write cache after (in seconds): 10
      Cache read ahead multiplier: 3
      Media scan enabled: true
      Media scan with parity check: false
      Management client attribute: 1759333852

You may also refer to <Document 1674848.1> Sun Storage 2500, 2500-M2, and 6000 Arrays: Performance is Slow on an Apparently Optimal Array for additional steps to verify write cache status.

Cause

The write cache gets suspended due to a known issue in 07.60.18.10 firmware and seen up to 07.60.56.10 firmware. For more details, refer to <Bug 15596492> SUNBT6891452 AFTER FIRMWARE UPDATE TO 7.60.18.10 WRITE CACHE IS SUSPENDED ON ON.

Solution

The permanent fix for this issue is integrated into 07.60.63.10 firmware or later.

For 6140/6540 arrays, the firmware revision 07.60.63.10 is bundled with CAM revision 6.9.0.18 or later.
For 6180/6580/6780 arrays, upgrade to 07.77.13.11 (bundled with CAM 6.8.0.20) or later.

To avoid the issue, download the latest CAM revision and then upgrade array baseline firmware. Refer to <Document 1296274.1> How to Download Common Array Manager (CAM) Software and Patches to identify the latest CAM version available and download instructions.

If the array is already upgraded to the affected firmware version and write cache is found to be disabled, Refer to <Document 1674848.1> Sun Storage 2500, 2500-M2, and 6000 Arrays: Performance is Slow on an Apparently Optimal Array for Resolution steps.

References

<NOTE:1674848.1> - Sun Storage 2500, 2500-M2, and 6000 Arrays: Performance is Slow on an Apparently Optimal Array
<BUG:15596492> - SUNBT6891452 AFTER FIRMWARE UPDATE TO 7.60.18.10 WRITE CACHE IS SUSPENDED ON ON
<NOTE:1607183.1> - Sun Storage 2500, 2500-M2, Flexline and 6000 Arrays: Understanding Cache Operation

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