Re: io size of Unix machine

Are you trying to find maximum size of the IO possible in Sun/Solaris ? Kernel parameter maxphys parameter determines the maximum size of the IO possible from the OS. By default, it is around 128k depending upon what hardware you use(sun4d=124k, sun4u=128ketc ). If you user veritas volume manager, then vol_maxio parameter is the maximum size of the IO possible through veritas layer. If you use disk suite then, md_maxphys is the maximum IO size. So, if you want to set your IO size, then set both parameters maxphys and vol_maxio to that value (assuming you are using veritas ). Also, I think, veritas has hard limit of 256k and Oracle has hard limit of 512k.

Your values should depend upon the type of application, type of disk drives, stripe width etc..

Thanks
Riyaj "Re-yas" Shamsudeen
Certified Oracle DBA
i2 technologies   www.i2.com

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How can I find the logical or physical I/O size on a Sun Solaris machine ? Thanks,
~aslam

Received on Wed May 30 2001 - 11:22:11 CDT