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IBM Tivoli Storage Manager FastBack 6.1: Local deduplicated data repositories may become corrupted during shutdown.

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Abstract

The IBM Tivoli Storage Manager (TSM) FastBack version 6.1 data deduplication repository may become corrupted during an abnormal shutdown of the deduplication repository service.

Content

Problem Summary:
The FastBack data deduplication repository may become corrupted during an abnormal shutdown of the deduplication repository service (FastBack Data Deduplication Service). The problem can occur when:

  1. The deduplication service (FastBack Data Deduplication Service) terminates as a result of a power failure to the FastBack Server.
  2. The deduplication service terminates abnormally as a result of a termination of the process.
  3. An attempt is made to shut down the deduplication service normally, but a time out occurs. This results in an abnormal termination of the service.

APAR IC81413 describes this problem.

Affected products
Tivoli Storage Manager FastBack versions 6.1.0 through 6.1.5.1 with Dedupe Repository enabled.

This problem is specific to local FastBack deduplication repositories. It does not affect users of WAN deduplication.

How to determine whether your deduplication repository is affected
When the FastBack Data Deduplication Service starts following an abnormal shutdown of the data deduplication service, look in the FastBack service log files for this entry:

INFO Recovering hashtable

If a message containing this text is found, the repository is corrupted and needs to be rebuilt. Please refer to the “How to avoid the problem” section, if you need to rebuild the repository.

Here is an example of a message that would indicate that the repository is corrupted:
2012-10-20 16:00:00.000+2:00 D:\sn\server\recovery.c process_recovery 700 VM-LAB1.COM INFO Recovering hashtable

If a similar message is not found, the repository is not affected.

Note: The FastBack data deduplication service log files are found at C:\Documents and Settings\All Users\Application Data\Tivoli\TSM\FastBack\sn.
For Microsoft Windows 7 and Windows 2008 the logs may be found at C:\Program​Data\Tivol​i\TSM\Fast​Back\sn.

How to avoid the problem:
Use the local FastBack repository in standard mode (NTFS repository), and not as a deduplication repository.

Recommended alternatives to deduplicated repositories:
  • Use NTFS compression to reduce the repository usage of the FastBack server. When Disaster Recovery (DR) is not required, additional data reduction is achieved by setting the Cleanup level to “High”.
  • Use other data reduction technologies such as hardware storage deduplication.

Fix:
Release:Vulnerable levels:First level with fix within that release:
Tivoli Storage Manager FastBack 6.1 6.1.0 through 6.1.5.16.1.5.2
Available on April 20, 2012 in Fix Central: www.ibm.com/support/fixcentral

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Document Information

Modified date:
25 September 2022

UID

swg21589848