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I have a fresh installation of AIX 7.1. I noticed that JFS2 file system with logging enabled (log=/dev/hd8) is dramatically slower than one with log=NULL. Simple zip archive extraction takes 5 minutes with logging enabled vs 5 seconds with no logging. I'm using standard 900 GB 10000 rpm SAS 2.5-inch SFF, G2, Hot-Swap Express, hard drive, option part number 81Y9927. AIX is running on LPAR. I've installed Centos 6.4 on the same LPAR and got almost same results. Extraction of the same zip archive takes about 5 seconds. This slowness affects everything including DB2 running on my AIX2. I tried to disable logging on my /var but after reboot all files gone from this directory.

My question is what is the best practice for optimizing I/O performance on AIX? I need to be able to continuously extract files, create and delete databases on my DB2 instance without loosing data after reboot. Thank you.

P.S. This video proves my concerns. But i need to be able to increase I/O performance system wide.

share|improve this question
/dev/hd8 - is this partition on the same disk where JFS2 partition is on? Try using another physical hard disk to let the logs be written in parallel. If possible please use an SSD to make it even faster. If this doesn't help then I can only assume the bottleneck is not I/O, but the CPU or memory in which case you need to upgrade them appropriately. – Sergiy Byelozyorov Mar 14 '14 at 0:42
Yes /dev/hd8 is on the same logical partition. I will try to put logs on separate hdd. Thanks @SergiyByelozyorov – vooD Mar 14 '14 at 1:54

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