Solved: Exacheck reports "FAIL Storage Server Check Exadata Smart Flash Cache should be actually used"

From: Yong Huang <"Yong>
Date: Tue, 17 Nov 2015 15:34:33 +0000 (UTC)
Message-ID: <1180300912.5768003.1447774473988.JavaMail.yahoo_at_mail.yahoo.com>

Three weeks ago I reported the titled problem. It was later found that the grid disk caching policy was set to 'none'. After changing it to 'default' caching policy, caching statistics started to show non-zero values:

CellCLI> alter griddisk DATA_CD_00_dmp2cel03 cachingPolicy="default"; GridDisk DATA_CD_00_dmp2cel03 successfully altered

CellCLI> list griddisk DATA_CD_00_dmp2cel03 detail
...

         cachingPolicy: default
...

CellCLI> list metriccurrent fc_by_used

         FC_BY_USED FLASHCACHE 6,690 MB On the compute node:

SQL> select * from gv$sysstat where name like '%cache%' and value > 0;

INST_ID STATISTIC# NAME                                 CLASS      VALUE    STAT_ID
------- ---------- ------------------------------------ ----- ---------- ----------
      1         58 cell writes to flash cache               8      21525  337656778  <-- before the change, only this stat was non-zero, contributed by LGWR only
      1         59 cell overwrites in flash cache           8       3849 2368027758
      1         60 cell partial writes in flash cache       8        166 1870362912
      1         85 db block gets from cache                 8 2848734343 4017839461

...

Oracle Support helped identify the cause of the problem. But we don't know why the default for us becomes 'none' instead of 'default', even after dropping and recreating the flashcache as instructed.

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Received on Tue Nov 17 2015 - 16:34:33 CET