Re: Oracle performance on RAID5 vs. multiple mirrored disks

gclayden_at_cwb.com (Giovanni Clayden) wrote in <387B0B9D.4DE0A60E_at_cwb.com>:
>I'm interested in views on the performance differences between Oracle on
>RAID5 vs. multiple mirrored disks. I'm aware that there is generally a
>write performance hit, with RAID, but how does RAID compare in terms of
>read performance? Can anyone share their experience?

i prefer raid-1 mirrors even though this wastes disk space. if you want to isolate disk use, as for example indexes from data, and logs from rollbacks, then you can arrange to have as many controller paths as you want, and mirror each. then you avoid channel and head conflicts.

my feeling about raid-5 is that you cannot avoid head conflicts since the essence of the technology is to stripe data across all the drives; hence any read/write moves all heads. this increases latency. --
dave mausner Received on Sat Jan 15 2000 - 14:41:19 CST