Re: ASM parameters

From: Mladen Gogala <mgogala_at_yahoo.com>
Date: 26 Jan 2008 15:30:27 GMT
Message-ID: <479b5213$0$1344$834e42db@reader.greatnowhere.com>


On Sat, 26 Jan 2008 15:18:09 +0000, Mladen Gogala wrote:

> However, ASM instance parameters are very poorly documented. There are
> no documents explaining how to monitor and change those parameters.
> Performance can be, as is the case with OCFS, abysmal if everything is
> left on default.

ASM instances also have wait interface. All of the classic wait event tables have their ASM counterparts. I looked into V$SYSTEM_EVENT table:

SQL> select event,time_waited from v$system_event order by 2 desc;

EVENT TIME_WAITED




rdbms ipc message 226141091
DIAG idle wait 20574722
pmon timer 20571058
gcs remote message 20568154
ges remote message 20523925
SQL*Net message from client 10515309
DFS lock handle 190351
PX Idle Wait 73904
kfk: async disk IO 27319
log write(even) 25253
log write(odd) 24735

EVENT TIME_WAITED




DBFG waiting for reply 9752
enq: AD - deallocate AU 6938
enq: AD - allocate AU 6467
enq: HD - contention 4561
ASM mount : wait for heartbeat 438
rdbms ipc reply 269
GCS lock open S 231
SQL*Net message to client 213

I wonder whether buffer cache hit ratio would make sense for the ASM instances and how to calculate it. I will let you know of my findings.

-- 
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Received on Sat Jan 26 2008 - 09:30:27 CST

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