After migration from Oracle ver 7.3.4 to 8.1.7.2 (32-bit) , %wio (%iowait)
on Database Machine Exceedingly High i.e. about 60 % .
NOTE - This is a Live Production Site .
AIX 4.3.3
Storage Box = SSA Class Storage (7133-D40 Model)
Machine S85 P-Series
Application - Banking (Hybrid)
SAMPLE Output Below %iowait = 60.5 % - (Detailed Output file Attached )
tty: tin tout avg-cpu: % user % sys % idle % iowait
1.2 10.0 8.9 21.8 8.9 60.5
Disks: % tm_act Kbps tps Kb_read Kb_wrtn
hdisk0 0.7 4.0 0.8 0 240
hdisk1 1.1 5.8 1.0 12 336
hdisk3 0.0 0.0 0.0 0 0
hdisk9 0.0 0.0 0.0 0 0
hdisk6 0.0 0.0 0.0 0 0
hdisk2 1.0 4.0 0.8 0 240
hdisk4 0.0 0.0 0.0 0 0
hdisk5 0.0 0.0 0.0 0 0
hdisk11 80.4 449.1 66.6 22292 4656
hdisk7 91.0 964.4 145.9 37868 19996
hdisk10 65.5 491.5 78.4 22916 6576
hdisk13 95.5 914.3 127.2 25656 29200
hdisk14 93.5 869.1 129.5 22824 29320
hdisk15 97.9 960.8 152.6 35620 22028
hdisk16 98.4 1382.8 174.7 53112 29856
hdisk8 75.0 802.9 119.4 40816 7360
cd0 0.0 0.0 0.0 0 0
------------------------------------------------------------------------------------
COMMENTS of Hardware Engineer :-
===============================
>From the perfpmr data collected on July 5th and it has
been analysed by our Labs.
The performance degradation is caused by fsync() routines called by Oracle
processes.
In 5 secs trace, fsync was called 276 times and consumed 21.39% CPU system
time.
The fsync() blocks the process until all the dirty pages are written to
the physical disks.
We checked the old perfpmr data collected with Oracle 7.3.4.5, it
doesn't have this issue.
Oracle has a fix to address the fsync problem on 8.1.7.2 (64-Bit) & 8.1.7.4 (32-Bit).
-------------------------------------------------------------------------------------
WE HAVE INITIATED WITH ORACLE CORP FOR A PATCH ON 8.1.7.2 32-BIT.
Nevertheless Any Other Ideas just in case the Patch Does NOT bring Down the %wio
Enough ?
NOTE - High %wio has been Observed only on AIX O.S. (NOT Other O.S.) post migration
to Oracle 8.1.7.2
--
Please see the official ORACLE-L FAQ: http://www.orafaq.com
--
Author: VIVEK_SHARMA
INET: [EMAIL PROTECTED]
Fat City Network Services -- (858) 538-5051 FAX: (858) 538-5051
San Diego, California -- Public Internet access / Mailing Lists
--------------------------------------------------------------------
To REMOVE yourself from this mailing list, send an E-Mail message
to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in
the message BODY, include a line containing: UNSUB ORACLE-L
(or the name of mailing list you want to be removed from). You may
also send the HELP command for other information (like subscribing).
