Array Firmware 3.2.0 through 3.2.6 May Cause Parity Mismatch on RAID 5 Volumes After Disk Replacement

Asset ID:	1-77-1001011.1
Update Date:	2011-02-21
Keywords:

Solution Type Sun Alert Sure

Solution 1001011.1 : Array Firmware 3.2.0 through 3.2.6 May Cause Parity Mismatch on RAID 5 Volumes After Disk Replacement

Related Items


Sun Storage 6320 System
 Sun Storage T3+ Array
 Sun Storage 6120 Array
 Sun Storage 6020 Array
 Sun Storage 6920 System

Related Categories


GCS>Sun Microsystems>Sun Alert>Criteria Category>Availability
 GCS>Sun Microsystems>Sun Alert>Release Phase>Resolved

PreviouslyPublishedAs
201337

Bug Id
<SUNBUG: 6499204>

Product
Sun StorageTek T3+ Array
Sun StorageTek 6120 Array
Sun StorageTek 6320 System
Sun StorageTek 6020 Array
Sun StorageTek 6920 System

Date of Workaround Release
29-AUG-2007

Date of Resolved Release
27-Oct-2008

Array Firmware 3.2.0 through 3.2.6 May Cause Parity Mismatch on RAID 5 Volumes After Disk Replacement

1. Impact

After completion of the copy process to a standby disk triggered by a failing disk or a manually issued "vol disable to_standby" on a RAID 5 volume, either a "disk scrubber" task or a manually issued "vol verify" may detect parity mismatches on the standby.

2. Contributing Factors

This issue can occur on the following platforms:

SPARC Platform

Sun StorageTek 6020, 6120, 6320, 6920 and T3+ with firmware versions 3.2.0 through 3.2.6

Notes:

The x86 platform is not affected by this issue.
This issue will only appear on a RAID 5 volume with the above listed arrays after a failing disk is copied to standby and the copy-back process has completed.

3. Symptoms

Following disk replacement, the copy-back process is started and completed. During the first "disk scrubber" task or a manually issued "vol verify", parity mismatches are reported in syslog, as in the following example:

    syslog: E: uXctr Vol verify detected data parity mismatch on Stripe: 0xXXXXXX

The parity information is not reliable until the "disk scrubber" or "vol verify" has recalculated the parity information for this volume. Parity mismatches only occur during the first "disk scrubber" task or manually issued "vol verify" after the copy to standby.

Note: If the first "disk scrubber" task or a manually issued "vol verify" has completed without error messages, the issue described has not occurred.

4. Workaround

To work around this issue:

After a failing disk has triggered a copy-to standby, abort the copy-to standby if it hasn't already finished.
Replace the failed disk so that a "parity reconstruct" is started.
If the copy-to-standby is finished, and a disk scrubbing task is not yet complete, abort the disk_scrubbing, pull the standby disk, and replace the failed disk so that a "parity reconstruct" is started.
Plug the standby disk back in.

Note: If the "disk scrubber" is disabled, "vol verify" should be run manually.

5. Resolution

This issue is addressed in the following release:

SPARC Platform

Sun StorageTek 6020, 6120, 6320 and 6920 with firmware version 3.2.7 (as delivered in patch 116931-23 or later)

Please see the "Workaround" section to address this issue for the T3+.

This Sun Alert notification is being provided to you on an "AS IS" basis. This Sun Alert notification may contain information provided by third parties. The issues described in this Sun Alert notification may or may not impact your system(s). Sun makes no representations, warranties, or guarantees as to the information contained herein. ANY AND ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, OR NON-INFRINGEMENT, ARE HEREBY DISCLAIMED. BY ACCESSING THIS DOCUMENT YOU ACKNOWLEDGE THAT SUN SHALL IN NO EVENT BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, PUNITIVE, OR CONSEQUENTIAL DAMAGES THAT ARISE OUT OF YOUR USE OR FAILURE TO USE THE INFORMATION CONTAINED HEREIN. This Sun Alert notification contains Sun proprietary and confidential information. It is being provided to you pursuant to the provisions of your agreement to purchase services from Sun, or, if you do not have such an agreement, the Sun.com Terms of Use. This Sun Alert notification may only be used for the purposes contemplated by these agreements.

Copyright 2000-2008 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, CA 95054 U.S.A. All rights reserved.

Modification History
16-Oct-2007: Updated Resolution Section
27-Oct-2008: No further updates needed, republish Resolved

References

<SUNPATCH: 116931-23>

Previously Published As
103056
Internal Comments
Please send technical questions to the following email:
sunalert-tech-questions@sun.com
and CC the following persons:
Internal Contributor/Submitter
Internal Eng Responsible Engineer
Internal Services Knowledge Engineer

Internal Contributor/submitter
Erhard.Pompe@sun.com

Internal Eng Business Unit Group
NWS (Network Storage)

Internal Eng Responsible Engineer
Erhard.Pompe@sun.com

Internal Services Knowledge Engineer
david.mariotto@sun.com

Internal Escalation ID
1-20699941

Internal Resolution Patches
116931-23

Internal Sun Alert Kasp Legacy ID
103056

Internal Sun Alert & FAB Admin Info
Critical Category: Availability ==> Pervasive
Significant Change Date: 2007-08-29
Avoidance: Patch, Workaround
Responsible Manager: Karl-Heinz.Wegener@Sun.COM
Original Admin Info: [WF 29-Aug-2007, dave m: review complete, release]
[WF 28-Aug-2007, dave m: send for review]
[WF 27-Aug-2007, dave m: draft created, request addtl info]
28-Oct-2008, david m: no further updates, republish resolved

References

SUNPATCH:116931-23

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