>> Would DIO/CIO help
Depends on the size of the writes / reads .. CIO is only really good with block sizes of 1MB and upwards ..
http://www-03.ibm.com/servers/aix/wh...b_perf_aix.pdf
Run filemon to see what is going on and what file/LV your bottleneck is and post some output ..
Spreading the LV over more spindles is going probably going to be the quick fix .. unless you have contention on the same file / inode .. (you can use splat to analyse this also) - and sync_release_ilock may also be an option.
http://publib.boulder.ibm.com/infoce...mds5/splat.htm
you can tune ioo if you know what types of writes / reads you are doing i.e. sequential reads and sequential write and random writes can be tuned a little (random reads cannot)
Rgds
Mark Taylor