Re: ASM I/O size

From: K Gopalakrishnan <>
Date: Sun, 6 Jul 2008 21:17:00 -0700 (PDT)
Message-ID: <>

ASM uses (by default) 1MB as the stripe size. It is called Allocation Unit (AU) in ASM terminology. This ASM AU size is (crudely) like your extent size for datafiles and ASM reads one extent at a time from a disk. Depending on how many disks you have you read n*1MB data per read. There is an 'asmiostat' in the 11g version and I am not aware of any such thing in your version.


On Jul 3, 4:25 pm, wrote:
> Hello,
> I'm running under 10.2 database on AIX5.3L
> I have disk group ASM_DATA which has 100 SAN equi-sized (256GB) disks/
> luns. with MBRC of 16 & Block size of 16K , When I read a table of
> 10GB via FTS, what should be my I/O size/lun ? Should my I/O size be
> same for all the LUNs?
> 1) ASM level
> 2) I/O stats (iostat -D )
> Thanks
Received on Sun Jul 06 2008 - 23:17:00 CDT

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