Re: Tuning PostgreSQL

> What would you guys think of not using RAID5 in that case, but just a really
> fast 15.000 rpm SCSI-320 disk?

I'd say you must be able to tolerate losing all the data since your last database backup. Your battery backed cache, rotational speed, and transfer rate aren't going to help at all when the drive itself degrades and corrupts data. If you can really only afford 3 drives, I'd have a single drive with the OS & WAL on it, and the data on a RAID-1 mirror set using the other 2 drives. If you need more space for data, or want your OS drives to be mirrored - it's going to cost more. See if you can get 2x18GB drives for the OS and 2x73GB drives for the data.

You have to consider how much headache that small amount of additional money is going to save you (and your users) down the road.

Roman

-----Original Message-----
From: Alexander Priem [mailto:ap(at)cict(dot)nl]
Sent: Mon 7/21/2003 5:43 AM
To: shridhar_daithankar(at)persistent(dot)co(dot)in; pgsql-performance(at)postgresql(dot)org
Cc:
Subject: Re: [PERFORM] Tuning PostgreSQL

Thanks, i'll look further into these mount setting.

I was just thinking, the server will have a (RAID) controller containing
128Mb of battery-backed cache memory. This would really speed up inserts to
the disk and would prevent data loss in case of a power-down also.

What would you guys think of not using RAID5 in that case, but just a really
fast 15.000 rpm SCSI-320 disk?

Kind regards,
Alexander.


----- Original Message -----
From: "Shridhar Daithankar" <shridhar_daithankar(at)persistent(dot)co(dot)in>
To: <pgsql-performance(at)postgresql(dot)org>
Sent: Monday, July 21, 2003 2:05 PM
Subject: Re: [PERFORM] Tuning PostgreSQL


> On 21 Jul 2003 at 13:45, Alexander Priem wrote:
>
> > So where can I set the noatime & data=writeback variables? They are not
> > PostgreSQL settings, but rather Linux settings, right? Where can I find
> > these?
>
> These are typicaly set in /etc/fstab.conf. These are mount settings. man
mount
> for more details.
>
> The second setting data=writeback is ext3 specific, IIRC.
>
> HTH
>
> Bye
> Shridhar
>
> --
> History tends to exaggerate. -- Col. Green, "The Savage Curtain", stardate
> 5906.4
>
>
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