Re: DASD Disk Layout Advice

From: joel garry <>
Date: Mon, 30 Nov 2009 10:00:47 -0800 (PST)
Message-ID: <>

On Nov 27, 7:45 am, Pat <> wrote:

> 3) RAID 5 ... with todays' controllers is that getting used more
> often? It was drilled into my head years ago that you don't put OLTP
> data on RAID 5, but then it was drilled into my head that you never
> mount your tablespace over NFS too and that changed :)

I'm a BAARFer by nature, but I have to admit, as long as it isn't in degraded mode and nobody does anything stupid like yanking out two drives and you aren't near saturating volumes of data movement, it actually works pretty well on at least the specific configuration we have, which is quite different than yours. Just get management to at least agree to go away from it if some actual evidence of severe performance degradation occurs. I see it during mass app upgrades, which do things like add columns to every row in the largest tables, but that just is a matter of waiting until things are done. Performance issues during normal ops seem to skew towards cpu issues, for my configuration. Generally they are due to DSS type operations on my OLTP system. Which are decided upon by management, so are easy to turn around into "hardware enhancement requirements."


-- is bogus.
Received on Mon Nov 30 2009 - 12:00:47 CST

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