Hi Guys, Have had a few people ask for the whys, see below:
Yeah performance is the main one, I have been told using zfs on a single slice will disable the write cache, not sure if there is a way around that. Also I have seen cases like Murray's suggested configuration where there will be multiple pools spanning multiple disks all running near capacity, having a single disk fail can be catastrophic for all pools involved in regards to data integrity and have seen it recently where data was not recoverable. Of course regular exports can help ease this worry though. But what it all comes down to is performance vs redundancy vs cost vs what hardware you actually have to use. Using 2 slices for 2 different rpools is a good idea for a test/learning environment, however in production I can see a newbie sys admin coming along and getting things mixed up like you say. *Regards* <http://www.sun.com> * Leigh Maddock * Email Address : leigh.maddock at sun.com <mailto:leigh.maddock at sun.com> Technical Solution Centre *Sun Microsystems* Australia : 1800-614-644 India : 1600-425-4786 New Zealand : 0800-275-786 Singapore : 1800-339-2786 <http://www.sun.com> ** Please note my current working hours are Tuesday - Saturday, 4pm - Midnight AEST. If you require support outside of these hours please call sun support to speak with the next available engineer.* Submit, update and view service tickets online <http://www.sun.com/service/online/> Search our knowledge base <http://sunsolve.sun.com/> Search our online manuals <http://docs.sun.com/> On 22/02/10 05:12 PM, Nathan Kroenert wrote: > Nice to see us all singing the same tune... > > Myself, I use a couple of 2.5" 320GB disks in a zfs mirror for boot, > and 500GB disks for my zpool for data... > > A note on the whole Sun not recommending individual slices though. > > It's important to consider *why* they don't recommend multiple zpools > on a single physical spindle... > > Leigh - I have my own ideas, but what is Sun's position on the why... > > Performance is the obvious one... > > (I actually have 2 150GB slices on my 320GB disks - and have my > current zpool on slice 0 (ie: at the start of the disk, and well away > fron the slower inner sectors). But I use slice 1 for an alternate > rpool when I feel like it - So it's actually nice. > > You just need to be a little careful not to get them mixed up. Like > trying to have to pools known as rpool on the same disk(s). > > ;) > > Nathan. > > Murray Blakeman wrote: >> Thanks for the responses J >> >> >> >> You have convinced me to add another 2 drives to use as a dedicated >> boot mirror pool. >> >> >> >> I?ve got room so why not. I?ll just use the excess space on the >> mirror as a place to backup files for more redundancy. >> >> >> >> Thanks >> >> >> >> >> >> *From:* ug-msosug-bounces at opensolaris.org >> [mailto:ug-msosug-bounces at opensolaris.org] *On Behalf Of *Leigh Maddock >> *Sent:* Monday, 22 February 2010 2:42 PM >> *To:* Gary R. Schmidt >> *Cc:* ug-msosug at opensolaris.org >> *Subject:* Re: [ug-msosug] zfs boot configuration >> >> >> >> On 22/02/10 02:35 PM, Gary R. Schmidt wrote: >> >> On Mon, February 22, 2010 13:21, Gavin Maltby wrote: >> >> >> On 22 February 2010 13:06, Murray Blakeman >> >> <Murray.Blakeman at synergy.com.au> >> <mailto:Murray.Blakeman at synergy.com.au> wrote: >> >> >> >> A 10GB Boot/Root pool mirrored across 5 drives >> >> >> You'll want a much bigger root pool that that, I suspect. 10G is >> (just) >> >> enough for a single boot environment, but it's always nice to >> >> have room for several. >> >> >> I always like to have physically separate root disks. If you have >> >> space for them I'd get a couple of smaller disks to act as >> >> a root mirror (e.g., I have 2 x 250GB drives for a mirrored >> >> rpool) and then use all of your big data disks in a data >> >> pool. >> >> >> >> Just to second what he said. >> >> >> >> I have 2x160Gb disks in a mirrored root pool, and (at the moment) >> 4x500Gb >> >> disks in a RAIDZ. >> >> >> >> Much safer as if something takes out my root, like a dud update or the >> >> like, my data space is safe(r). >> >> >> >> Also, IIRC, ZFS works better when given *entire* disks to work with, >> >> rather than slices. >> >> >> >> Cheers, >> >> Gary B-) >> >> >> Just to confirm what the others have said, it is not a recommendation >> of SUN (even though it is possible) to use pools on individual slices. >> Using a root pool on separate disks would be a much better option, if >> available and is a SUN recommended configuration. >> >> Cheers, >> Leigh >> >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> ug-msosug mailing list >> ug-msosug at opensolaris.org >> http://mail.opensolaris.org/mailman/listinfo/ug-msosug -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.opensolaris.org/pipermail/ug-msosug/attachments/20100222/26841820/attachment.html>
