ServeRAID M5000 Series Advance Feature Key (46M0930) potential data loss after power failure - IBM System x



Source

RETAIN tip: H201788

Symptom

There is a low probability of data corruption in the ServeRAID M5000 after a power failure event. ServeRAID M5000 Series controllers without the ServeRAID M5000 Series Performance Accelerator Key are not affected.

Affected configurations

The system may be any of the following IBM servers:

  • System x3200 M3, type 7327, any model
  • System x3200 M3, type 7328, any model
  • System x3250 M3, type 4251, any model
  • System x3250 M3, type 4252, any model
  • System x3400 M2, type 7836, any model
  • System x3400 M2, type 7837, any model
  • System x3400 M3, type 7378, any model
  • System x3400 M3, type 7379, any model
  • System x3500 M3, type 7380, any model
  • System x3500, type 7977, any model
  • System x3550 M2, type 4198, any model
  • System x3550 M2, type 7946, any model
  • System x3550 M3, type 4254, any model
  • System x3550 M3, type 7944, any model
  • System x3620 M3, type 7376, any model
  • System x3630 M3, type 7377, any model
  • System x3650 M2, type 4199, any model
  • System x3650 M2, type 7947, any model
  • System x3650 M3, type 4255, any model
  • System x3650 M3, type 7945, any model
  • System x3690 X5, type 7148, any model
  • System x3690 X5, type 7149, any model
  • System x3850 X5, type 7145, any model
  • System x3850 X5, type 7146, any model

The system is configured with one or more of the following IBM Options:

  • ServeRAID M5000 Series Advance Feature Key, Option part number 46M0930, any replacement part number (CRU)

This tip is not software specific.

  • The 12.7.0-0020 firmware for the M5000 Series Controller is affected.

Solution

This behavior has been corrected in ServeRAID M5000 Series SAS/SATA Controller firmware 12.12.0-0037.

The file is or will be available by selecting the appropriate Product name, Product machine type, and Operating system on IBM Support's Fix Central web page, at the following URL:

Workaround

IBM strongly recommends attaching your server to an Uninterruptible Power Supply (UPS).

Additional information

After power from the system is lost, write data that has not yet been written to the drives remains in the controllers' on-board cache and is retained for a period of time determined by the battery life. Once power is restored, the cache write data is written to the drives.

With firmware 12.7.0-0020, if the operating system issues an I/O command while the controller is writing the cache data to the same location, then the data written to the location and/or returned to the operating system may be corrupted. There is a very low probability of this occurring.

Under normal circumstances, disk locations with data in the write cache are properly locked to prevent a collision of system and controller activity. The latest release of the M5000 series firmware fixes this issue by correctly locking the locations with data in the cache.

 

Applicable countries and regions

 


Document id:  MIGR-5086672
Last modified:  2011-02-14
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