Oracle and LV

[Michael Tully]

You would have a better chance of disk I/O balance by having a large number of LUN's and striping across the whole lot.

e.g for 32 LUN's using 64k stripe size.

lvcreate -n -i 32 -I 64 -l /dev/myvg

The also have a look at scsictl queue depths. The default is 8, but I would suggest 16.

[Ted Buis]

RAID 5 is "so fast" on clariion only by comparison to RAID S on Symmetrix. Cache can mask the write penalty, but if you are doing enough writes, the cache runs out of space and you are left with the back end performance of the array, which is mostly dictated by the number of spindles. Benchmarks are always done with many spindles, so beware, if the number of disks in the RAID group is less than what you had on the Symmetrix for the equivalent data.