| From: | Greg Stark <gsstark(at)mit(dot)edu> |
|---|---|
| To: | Jan Dittmer <j(dot)dittmer(at)portrix(dot)net> |
| Cc: | "Joshua D(dot) Drake" <jd(at)commandprompt(dot)com>, Christopher Browne <cbbrowne(at)acm(dot)org>, pgsql-performance(at)postgresql(dot)org |
| Subject: | Re: which dual-CPU hardware/OS is fastest for PostgreSQL? |
| Date: | 2005-01-14 16:29:20 |
| Message-ID: | 87is60ug7z.fsf@stark.xeocode.com |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-performance |
Jan Dittmer <j(dot)dittmer(at)portrix(dot)net> writes:
> You could always do raid 1 over raid 0, with newer kernels (2.6ish)
> there is even a dedicated raid10 driver.
Aren't you much better off doing raid 0 over raid 1?
With raid 1 over raid 0 you're mirroring two stripe sets. That means if any
drive from the first stripe set goes you lose the whole side of the mirror. If
any drive of the second stripe set goes you lost your array. Even if they're
not the same position in the array.
If you do raid 0 over raid 1 then you're striping a series of mirrored drives.
So if any drive fails you only lose that drive from the stripe set. If another
drive fails then you're ok as long as it isn't the specific drive that was
paired with the first failed drive.
--
greg
| From | Date | Subject | |
|---|---|---|---|
| Next Message | Merlin Moncure | 2005-01-14 17:22:50 | Re: which dual-CPU hardware/OS is fastest for PostgreSQL? |
| Previous Message | Alex Turner | 2005-01-14 15:58:30 | Re: which dual-CPU hardware/OS is fastest for PostgreSQL? |