ASM Rebalance Poor Performance (Doc ID 1427503.1)

Last updated on OCTOBER 31, 2016

Applies to:

Oracle Database - Enterprise Edition - Version 11.1.0.7 and later
Information in this document applies to any platform.
***Checked for relevance on 07-Aug-2013***

Symptoms

1. This issue only happens with 11.1.0.7 ASM as this issue is fixed in 11.1.0.7.1

2. Rebalancing performance is getting slower over time and v$asm_operation.est_rate shows less than 1000 and the value gets decreasing over time.
In some cases, the rebalance is completed in a few days but most of time it fails with ORA-04031 or ORA-00600[723].

Please note that the value of EST_RATE is decreasing from 4505 tp 73 and EST_MINUTES is increasing from 530 to 3081 over time within 5 hours from v$asm_operation view.

Time           G_N Oper   State Power     Actual    Sofar Est_Work Est_Rate Est_Min
Jan 9 10:54:05 1 REBAL RUN      10           10   13312 2439430       4505      530 <<<< Started with 4505
Jan 9 11:01:00 1 REBAL RUN      10           10   32590 2439432       2104    1146
Jan 9 11:30:00 1 REBAL RUN      10           10   71978 2439447        953     2497
Jan 9 12:01:00 1 REBAL RUN      10           10   98256 2439454        710     3322
Jan 9 12:30:00 1 REBAL RUN      10           10   17412 2439437        608     3833
Jan 9 13:01:00 1 REBAL RUN      10           10  135251 2439453       519      4451
Jan 9 13:30:00 1 REBAL RUN      10           10  150034 2439455       478     4793
Jan 9 14:01:00 1 REBAL RUN      10           10  163919 2439470       415     5463
Jan 9 14:30:00 1 REBAL RUN      10           10  169920 2439469       403     5709
Jan 9 14:32:31 1 REBAL RUN      10           10       240   182279       142     1259
Jan 9 15:01:00 1 REBAL RUN      10           10     3720   191643       112     1749
Jan 9 15:30:00 1 REBAL RUN      10           10     5040   196994         73     3081 <<<< Ended with 73



3. The following similar error occurs in ASM alert.log during rebalance.

ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67708
ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67651
ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67655
ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67659
ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67881
ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67745
ERROR: Releasing group with AU enqueue for extent gn=3 disk=5 au=67718



4. The usage of following resources below from v$sgastat keeps increasing over time during rebalancing.

- shared pool ges resource
- shared pool ges enqueues
- shared pool KFD extent enqueue obj
- shared pool free memory


Please note that "KFD extent enqueue obj" resource started with 5M and ended with 120M and "ges resource" from 4M to 50M over time within 5 hours v$sgastat view.

Jan 9 10:53:00 shared pool KFD extent enqueue obj 5902696
Jan 9 10:54:01 shared pool KFD extent enqueue obj 9011376
Jan 9 10:55:00 shared pool KFD extent enqueue obj 11485624
..
Jan 9 15:49:00 shared pool KFD extent enqueue obj 119863312
Jan 9 15:50:00 shared pool KFD extent enqueue obj 119892440
Jan 9 15:51:00 shared pool KFD extent enqueue obj 119924216
.
.
Jan 9 10:53:00 shared pool ges resource 4095280
Jan 9 10:54:01 shared pool ges resource 5370008
Jan 9 10:55:00 shared pool ges resource 6437088
Jan 9 10:56:00 shared pool ges resource 7354200
..
Jan 9 15:49:00 shared pool ges resource 51479400
Jan 9 15:50:00 shared pool ges resource 51502472
Jan 9 15:51:00 shared pool ges resource 51508240



Cause

Sign In with your My Oracle Support account

Don't have a My Oracle Support account? Click to get started

My Oracle Support provides customers with access to over a
Million Knowledge Articles and hundreds of Community platforms