Re: Log file I/O throughput

From: billjohnson <member45480_at_dbforums.com>
Date: Thu, 23 Oct 2003 15:58:28 -0400
Message-ID: <3516938.1066939108@dbforums.com>

Ok - I read through the replies and there seems to be a fair amount of discussion regarding hardware. I have heard the same song and dance from our UNIX Admin team that the Disk I/O is raid-1, HP Disk, dedicated drives....for our redo logs. We are seeing 30% of the DB time in a statspack report going to "log file sync" wait. It just jumped through the roof from 5% about 1 week ago. I need to find some other measurement that will allow me to confirm whether this is a hardware issue or a program commit/update issue. When looking at the stats pack report, the "user commits" line shows the following:

Statistic                                    Total   per Second    per

Trans

• ---------------- ------------ ------------

user commits                                92,676         25.7

1.0

This number is no different in average commits per second than then the system was only spending 5% of the overall time in log file sync wait. I need some additional direction on nailing down the real source of the problem. This is a 16-way RP-8400 HP-UX 11.i environment running SAP 4.0B on an Oracle 8.1.7.3 instance. We have about 5,000 users on this system. Any ideas? I am a DBA - not a UNIX Admin.

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Posted via http://dbforums.com Received on Thu Oct 23 2003 - 14:58:28 CDT