Re: RAID: Advantage or disaster?

From: Geoff Reader <grr_at_NOSPAM.bton.ac.uk>
Date: Wed, 05 Dec 2001 13:19:53 +0000
Message-ID: <3C0E1EF9.2EE88241@NOSPAM.bton.ac.uk>

We had similar problems with a database here, that had all the data files on the same filesystem.
If you look at File IO, you may find its one file causing most of the bottleneck. In our case it was TEMP.
So we moved this onto another filesystem (not raided incidentally as its write intensive). And no more problems... Heres teh File IO SQL to be run as system, it works on 7.3.4 and I think on 8i, I'm not certain of that mind.
Good luck.

 SELECT name, phyrds, phyrds * 100 / trw.phys_reads read_pct,

              phywrts,  phywrts * 100 / trw.phys_wrts write_pct,
                db.tablespace_name

   FROM tot_read_writes trw, v$datafile df, v$filestat fs,dba_data_files db
  WHERE df.file# = fs.file#
  and df.file# = file_id

Geoff
Geoff Reader
University of Brighton

Andy Kent wrote:
>
> What do people think about the use of RAID for an IDS database these days?
> Better, worse, or about the same on balance as JABOD? Any RAID levels to
> prefer / avoid?
>
> A client of mine is running RAID 5 on Compaq, and is getting 100% disk i/o
> and frequent crashes. I haven't been able to look closely enough to
> establish whether it's the RAID 5 that's causing this, but anyway they're
> moving to a bigger box and planning to go RAID 5 again.
>
> Conventional wisdom and past experience tells me this would be a disaster.
> Has the technology moved on so as to tip the scales?
>
> --
> -Andy Kent-
> Bristol, England
>
> Remove '.DontSpamMe' from return address to respond.
Received on Wed Dec 05 2001 - 07:19:53 CST