Re: [Testperf-general] dbt2 & opteron performance
От | Jim C. Nasby |
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Тема | Re: [Testperf-general] dbt2 & opteron performance |
Дата | |
Msg-id | 20050729193908.GA95931@decibel.org обсуждение исходный текст |
Ответ на | Re: [Testperf-general] dbt2 & opteron performance (Mark Wong <markw@osdl.org>) |
Ответы |
Re: [Testperf-general] dbt2 & opteron performance
(Mark Wong <markw@osdl.org>)
|
Список | pgsql-hackers |
On Thu, Jul 28, 2005 at 05:00:44PM -0700, Mark Wong wrote: > On Thu, 28 Jul 2005 16:55:55 -0700 > Mark Wong <markw@osdl.org> wrote: > > > On Thu, 28 Jul 2005 18:48:09 -0500 > > "Jim C. Nasby" <decibel@decibel.org> wrote: > > > > > On Thu, Jul 28, 2005 at 04:15:31PM -0700, Mark Wong wrote: > > > > On Thu, 28 Jul 2005 17:17:25 -0500 > > > > "Jim C. Nasby" <decibel@decibel.org> wrote: > > > > > > > > > On Wed, Jul 27, 2005 at 07:32:34PM -0700, Josh Berkus wrote: > > > > > > > This 4-way has 8GB of memory and four Adaptec 2200s controllers attached > > > > > > > to 80 spindles (eight 10-disk arrays). For those familiar with the > > > > > > > schema, here is a visual of the disk layout: > > > > > > > http://www.osdl.org/projects/dbt2dev/results/dev4-015/layout-6.html > > > > > > > > > > Have you by-chance tried it with the logs and data just going to > > > > > seperate RAID10s? I'm wondering if a large RAID10 would do a better job > > > > > of spreading the load than segmenting things to specific drives. > > > > > > > > No, haven't tried that. That would reduce my number of spindles as I > > > > scale up. ;) I have the disks attached as JBODs and use LVM2 to stripe > > > > the disks together. > > > > > > I'm confused... why would it reduce the number of spindles? Is > > > everything just striped right now? You could always s/RAID10/RAID0/. > > > > RAID10 requires a minimum of 4 devices per LUN, I think. At least 2 > > devices in a mirror, at least 2 mirrored devices to stripe. > > > > RAID0 wouldn't be any different than what I have now, except if I use > > hardware RAID I can't stripe across controllers. That's treating LVM2 > > striping equal to software RAID0 of course. > > Oops, spindles was the wrong word to describe what I was losing. But I > wouldn't be able to spread the reads/writes across as many spindles if I > have any mirroring. Not sure I fully understand what you're trying to say, but it seems like it might still be worth trying my original idea of just turning all 80 disks into one giant RAID0/striped array and see how much more bandwidth you get out of that. At a minimum it would allow you to utilize the remaining spindles, which appear to be unused right now. -- Jim C. Nasby, Database Consultant decibel@decibel.org Give your computer some brain candy! www.distributed.net Team #1828 Windows: "Where do you want to go today?" Linux: "Where do you want to go tomorrow?" FreeBSD: "Are you guys coming, or what?"
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