Friday, February 12, 2016

How to resolve error "CELL-02772: Cannot create or alter flash cache due to unequal cell disk sizes."

Flash F40 cards may come from field replacement stock with FMOD's that have been through a complete erasure process using a Secure Erase method that ensures absolutely no data is left on the device). In some cases, the secure erase procedure could cause the visible size of the FMOD's to change to a capacity slightly larger than expected. This happened because a configuration part of the device was being reset as a result of the Secure Erase needing to touch every sector on the FMOD.
On Engineered Systems (Exadata, Sparc SuperCluster, Exaltyics) use the "ddoemcli" utility to change the "max visible sectors" to the correct setting.
For non-Engineered Systems there has been provided another solution to the problem using the linux hdparm utility to change the "maximum visible sectors" to the expected size.

# cellcli -e create flashcache all
CELL-02772: Cannot create or alter flash cache due to unequal cell disk sizes.
[root@mytestkit ~]#

Line 176: lunSize: 93.13225793838501G
Line 187: lunSize: 93.13225793838501G
Line 198: lunSize: 93.13225793838501G
Line 209: lunSize: 93.13225793838501G
Line 220: lunSize: 93.13225793838501G
Line 231: lunSize: 93.13225793838501G
Line 242: lunSize: 93.13225793838501G
Line 253: lunSize: 93.13225793838501G
Line 264: lunSize: 93.1604232788086G
Line 275: lunSize: 93.1604232788086G
Line 286: lunSize: 93.1604232788086G
Line 297: lunSize: 93.1604232788086G
Line 308: lunSize: 93.13225793838501G
Line 319: lunSize: 93.13225793838501G
Line 330: lunSize: 93.13225793838501G
Line 341: lunSize: 93.13225793838501G

== Action Plan ===

Using the "ddoemcli" utility
NOTE - ENSURE THAT THE AFFECTED FLASH MODULES ARE DROPPED FROM ASM. (This should have been done automatically upon failure)
1. Read the current maximum visible sectors of the FMOD using the "DDOEMCLI" Command
./ddoemcli -c 1 -list
(-c 1 = controller 1, -list means list all output)
NOTE - Flash Card slot # does not match the controller #
F40 slot 1 = controller 3
F40 Slot 2 = controller 4
F40 slot 4 = controller 2
F40 slot 5 = controller 1

2. Change the maximum user addressable LBAs to the LSI factory setting using DDOEMCLI -c # -format -op -MaxLBA command:
[root@mytestkit ~]# ./ddoemcli -c 1 -format -slot 4 -op -maxlba 195312500 -s
LSI Corporation WarpDrive Management Utility
Version (2013.08.12)
Copyright (c) 2013 LSI Corporation. All Rights Reserved.
LSI WarpDrive Management Utility: Please wait. Format of WarpDrive is in
Selected over-provisioning level change is done successfully.
LSI WarpDrive Management Utility: WarpDrive format successfully completed.
LSI WarpDrive Management Utility: Execution completed successfully.

The BOLDED text above is the command used to correctly program the MaxLBA value.
3. Repeat steps for any other FMOD's on the F40 controller that also need to be adjusted.
Typically the 4 FMOD's are numbered slots 4, 5, 6 and 7 on each F40 card.

When completed, all Flash Disks should show the same size, as shown in the below example:
CellCLI> LIST PHYSICALDISK attributes name ,physicalSize where name like '.*FLASH.*'

For more detail refer to  ( Doc ID 1671022.1 )

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