Currently we have 2 x 140GB drives reserved for REDO directly attached.
I'm very much considering moving to raw for redo logs. We have 6 independant drives (each 140GB) on a fibre back plane - direct attached, not SAN. I don't think the array controller is a bottleneck - it would not even break into a sweat with 6 drives.
Q. How would I configure them? My thoughts are:
Three sets of mirrored drives. Each mirror contains a log member.
i.e.
Drive 1 - REDO1A
Drive 2 - REDO1B
Drive 3 - REDO2A
Drive 4 - REDO2B
Drive 5 - REDO3A
Drive 6 - REDO3B
and then Drive 1 & 2 would contain REDO4A/B, drive 3 & 4 REDO05A/B and drive 5 & 6 REDO06A/B to give 6 members - each 256MB in size to keep the 15 minute switch rate.
Archiving goes to a 470GB 9*72GB RAID5 array (and soon to a Standby server over the WAN)
Afriad my SUN hardware knowledge is a bit basic - I have experienced engineers to do the physical stuff - but they don't know Oracle very well!
So - do we think this REDO configuration allow us to do DML during the working day without killing the OLTP users?
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Guy Wicks
Database Manager
The British Library