High "log file sync" wait in HP-UX Benchmark ?

From: VIVEK_SHARMA <VIVEK_SHARMA_at_infosys.com>
Date: Thu, 22 May 2008 01:30:10 +0530
Message-ID: <69E1360E54B50C4A828A136C158E474203AA950DC2@BLRKECMBX02.ad.infosys.com>

Folks

During a Benchmark, High "log file sync" wait is observed for OLTP Transactions

Qs 1 What is the Solaris "maxphys" equivalent parameter on HP-UX 11.31? .. Increasing this had helped. Qs 2 Will moving the Online Redo logfiles from Mounted Filesystem to RAW Devices help? ... This had significantly helped in the Solaris case since Oracle was using pwrite() function call to write to redo logfiles on Mounted Filesystem , while another function call (forgot which) was used to write to redo logfiles after they were moved to RAW Devices. Qs 3 Since the Entire Set of Hard Disks is on RAID 5, could this be a significant cause for High logfile sync wait? NOTE - Storage Box = HP EVA 600 SAN Storage Box RAID 5 setup using SAME thereby consuming all of the 24 Hard Disks in the Box

Will provide Statspack Report as needed.

Cheers & Thanks in Advance

Vivek

P.S.
Config:-
Oracle 10.2.0.3
HP-UX 11.31
Application - Hybrid Banking Product

SP Report:-

Top 5 Timed Events                                                    Avg %Total
~~~~~~~~~~~~~~~~~~                                                   wait   Call
Event                                            Waits    Time (s)   (ms)   Time


----------------------------------------- ------------ ----------- ------ ------

log file sync                                  178,131       1,659      9   52.0
CPU time                                                       972          30.5
log file parallel write                        140,197         240      2    7.5
cursor: pin S                                  888,008         147      0    4.6
db file sequential read                         43,218          77      2    2.4
          -------------------------------------------------------------

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http://www.freelists.org/webpage/oracle-l Received on Wed May 21 2008 - 15:00:10 CDT