System panics and warning messages on the host Operating System may occur due to a filesystem reading and acting on incorrect data from the disk or a user application reading and acting on incorrect data from the array.

This issue can occur on the following platforms:

• Sun StorEdge 3310 (SCSI) Array with firmware version 4.11K/4.13B/4.15F (as delivered in patch 113722-10 through 113722-15)
• Sun StorageTek 3320 (SCSI) Array with firmware version 4.12E (as shipped)/ 4.15G (as delivered in patch 113730-01)
• Sun StorageTek 3510 3510 (FC) Array with firmware version 4.11I/4.13C/4.15F (as delivered in patch 113723-10 through 113723-16)
• Sun StorageTek 3511 (FC) Array with firmware version 4.11I/4.13C/4.15F (as delivered in patch 113724-04 through 113724-09)

The above raid arrays (single or double controller) with "Write-Back Caching" enabled on Raid 5 LUNs (or other raid level LUNs and an array disk administration action occurs), can return stale data when the I/O contains writes and reads in a very specific pattern. This pattern has been observed in both QFS and UFS metadata updates, and could be seen in other situations.

Filesystem warnings and panics occur and with no indication of an underlying storage issue. For UFS these messages could include:

   "panic: Freeing Free Frag"
   WARNING: /<mount point>: unexpected allocated inode XXXXXX, run fsck(1M) -o f
   WARNING: /<mount point>: unexpected free inode XXXXXX, run fsck(1M) -o f

This list is not exhaustive and other symptoms of stale data read might be seen.

Disable the "Write-Back Caching" option inside the array using your preferred array administration tool (sccli(1M) or telnet). This workaround can be removed on final resolution.

Use ZFS to detect (and correct if configured) the Data Integrity Events.

If not using a filesystem make sure your application has checksums and identity information embedded in its disk data so it can detect Data Integrity Events.

Migrating back to 3.X firmware is a major task and is not recommended.

This issue is addressed on the following platforms:

• Sun StorEdge 3310 (SCSI) Array with firmware version 4.15G (as delivered in patch 113722-16) or later
• Sun StorageTek 3320 (SCSI) Array with firmware version 4.15H (as delivered in patch 113730-02) or later
• Sun StorageTek 3510 3510 (FC) Array with firmware version 4.15G (as delivered in patch 113723-17) or later
• Sun StorageTek 3511 (FC) Array with firmware version 4.15G (as delivered in patch 113724-10) or later

• Updated Contributing Factors and Resolution sections
• State: Resolved

• Updated Contributing Factors section

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