Re: Raid performace issues (Raid 5 vs. Raid 0+1) with database files

I would like to hear your results using raid 5 for redo logs.

As far as should you or shouldn't you mirror temp. The question can only be, can you afford to have the system crash without warning. Is so, you can probably get by without mirroring temp or rollback. You just may crash.

Martin Hepworth <maxsec_at_usa.net> wrote in message news:37CCD323.5D644363_at_usa.net...
> NetComrade wrote:
> >
> > Hi folks,
> >
> > We are thinking to place one of our DB's on a Sun Storedge 5200 and
> > Sun Enterprise 4500.
> >
> > Since we have a web-based OLTP environment, well, actually mixed,
> > since we have major updates running at nights against most of the
> > data, I thought that RAID-5 is not great, since during the day there
> > are a lot of small reads/writes.
> > I was thinking about 0+1 on datafiles with actualy data, but I am not
> > sure whether I need to mirror the TEMP tablespace or whether I should
> > place the REDO logs on the mirror.
> >
> > Any advice would be appreciated.
> >
> > Thanx
> > ---------------
> > Andrey Dmitriev eFax: (978) 383-5892 Daytime: (917) 373-5417
> > AOL: NetComrade ICQ: 11340726 remove NSPAM to email
>
> HI
> Well I'm doing similar and am about to test various combinations...right
> now I'm going for 2x RAID5 sets, 1 for the data and 1 for the redo logs.
> With the 5200 you have hardware RAID5 so writing should be nice and
> fast, not that much different from 0+1, and RAID 0+1 is probably not
> justifiable for extra tiny perf gain agianst cost of disks.
>
> But like I said I'm going to test a few combinations and see what
> happens. If you want to pool test results contact me via email.
>
> Martin
Received on Wed Sep 01 1999 - 06:16:34 CDT