Fixes are available
APAR status
Closed as program error.
Error description
It is possible that a backlog of dereferenced deduplicated chunks might occur after a large amount of data is deleted. The deletion might occur as a result of expiration or by an explicit deletion request such as DELETE VOLUME or DELETE FILESPACE. The result will be that there are hundreds of millions of chunks to be processed by the background deletion engine. The backlog and lack of progress can be confirmed with the output from the SHOW DEDUPDELETEINFO command. The key column to look at is the "Number of chunks waiting in queue" as that will show hundreds of millions of chunks and will continue to increase over time. Example: tsm: SERVER>show dedupdelete ****Dedup Deletion General Status**** Number of worker threads : 16 Number of active worker threads : 2 Number of chunks waiting in queue : 583397475 NOTE: The abnormally large backlog does not usually occur from a standard expiration of deduplicated objects. In order to be affected by this APAR an abnormal amount of objects would have to be deleted from the server system. In some cases, this has come from the movement of deduplicated data OUT of a storage pool which leads to the same dereferencing action as an explicit deletion request such as expire, delete volume, delete filespace, etc.. Tivoli Storage Manager Versions Affected: 6.1, 6.2 and 6.3 Initial Impact: Medium Additional Keywords: performance, dedup, cleanup, chunks, dedupe, degrade, degradation, slow, hung, hang, perf
Local fix
Problem summary
**************************************************************** * USERS AFFECTED: All Tivoli Storage Manager server users. * **************************************************************** * PROBLEM DESCRIPTION: See error description. * **************************************************************** * RECOMMENDATION: Apply fixing level when available. This * * problem is currently projected to be fixed * * in levels 6.3.4.300, 6.3.5, and 7.1.1. * * Note that this is subject to change at the * * discretion of IBM. * **************************************************************** *
Problem conclusion
This problem was fixed.
Temporary fix
Comments
APAR Information
APAR number
IC97618
Reported component name
TSM SERVER
Reported component ID
5698ISMSV
Reported release
63W
Status
CLOSED PER
PE
NoPE
HIPER
NoHIPER
Special Attention
NoSpecatt
Submitted date
2013-11-12
Closed date
2013-11-14
Last modified date
2013-12-06
APAR is sysrouted FROM one or more of the following:
APAR is sysrouted TO one or more of the following:
Fix information
Fixed component name
TSM SERVER
Fixed component ID
5698ISMSV
Applicable component levels
R63A PSY
UP
R63H PSY
UP
R63L PSY
UP
R63S PSY
UP
R63W PSY
UP
R71A PSY
UP
R71H PSY
UP
R71L PSY
UP
R71S PSY
UP
R71W PSY
UP
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Document Information
Modified date:
06 December 2013