Re: DASD Disk Layout Advice

From: hpuxrac <>
Date: Wed, 25 Nov 2009 14:43:23 -0800 (PST)
Message-ID: <>

On Nov 24, 10:18 pm, Pat <> wrote:


> For the last few years, I've largely been laying out Oracle storage on
> SAN's, rather than on DASD, so I'm feeling a bit out of practise with
> today's drives and drive arrays.
> To make a long story short, I've got a new Oracle server in a remote
> data center that I didn't order or configure; it comes like it comes.
> Its a 32G 8 core intel box with 8 300G 15k SAS drives in it and a
> decent raid controller. Database in question is somewhere between a
> data warehouse and OLTP e.g. its read heavy, but there's still a very
> significant amount of write activity.
> I've got a colleague who, wants to build out the box something like:
> Disk0 .. RedoA
> Disk1 .. RedoB
> Disks 2..3 RAID 1 OS and Index tablespace
> Disks 4..7 Raid 10 Data tablespace
> My instinct is that buildout "wastes" too many spindles and ends up
> starving the index and data volumes.
> The counterproposal is to just make one big raid group like:
> Disk 0..7 Raid 10
> What are folks doing these days with these bold 'old 300G disks? It
> seems supremely wasteful to use an entire 300G drive hold 20G worth of
> red.
> Any recommendations, advice, etc would be appreciated.

You are kind of limited from the get go with 8 disks.

Is the application "commit happy"? Lots of single row updates followed by commits? In that case you might really want 2 dedicated disks RAID 1 for online logs to reduce the impact of log file sync.

Where is the operating system and swap space going to go?

Are you going to use hot spares or if not how are you going to monitor when ( not if ) a disk fails?

Your idea of using all 8 disks in a RAID 10 is probably the way I might lean unless you are aware that the app is real commit happy. Received on Wed Nov 25 2009 - 16:43:23 CST

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