>>> Christian Balzer <chibi@xxxxxxx> schrieb am Donnerstag, 14. Juli 2016 um 05:05: Hello, > Hello, > > On Wed, 13 Jul 2016 09:34:35 +0000 Ashley Merrick wrote: > >> Hello, >> >> Looking at using 2 x 960GB SSD's (SM863) >> > Massive overkill. > >> Reason for larger is I was thinking would be better off with them in Raid 1 > so enough space for OS and all Journals. >> > As I pointed out several times in this ML, Ceph journal usage rarely > exceeds hundreds of MB, let alone several GB with default parameters. > So 10GB per journal is plenty, unless you're doing something very special > (and you aren't with normal HDDs as OSDs). > >> Instead am I better off using 2 x 200GB S3700's instead, with 5 disks per a > SSD? >> > S3700s are unfortunately EOL'ed, the 200GB ones were great at 375MB/s. > 200GB S3710s are about on par for 5 HDDs at 300MB/s, but if you can afford > it and have a 10Gb/s network, the 400GB ones at 470MB/s would be optimal. > > As for sharing the SSDs with OS, I do that all the time, the minute > logging of a storage node really has next to no impact. > > I prefer this over using DoMs for reasons of: > 1. Redundancy > 2. hot-swapability > > If you go the DoM route, make sure it's size AND endurance are a match for > what you need. > This is especially important if you were to run a MON on those machines as > well. > Cause we had to change some DoM's due to heavy MON logging, how do you configure MON logging? On that redundant SSD's or remote? Steffen > Christian > >> Thanks, >> Ashley >> >> -----Original Message----- >> From: Christian Balzer [mailto:chibi@xxxxxxx] >> Sent: 13 July 2016 01:12 >> To: ceph-users@xxxxxxxxxxxxxx >> Cc: Wido den Hollander <wido@xxxxxxxx>; Ashley Merrick <ashley@xxxxxxxxxxxxxx> >> Subject: Re: SSD Journal >> >> >> Hello, >> >> On Tue, 12 Jul 2016 19:14:14 +0200 (CEST) Wido den Hollander wrote: >> >> > >> > > Op 12 juli 2016 om 15:31 schreef Ashley Merrick <ashley@xxxxxxxxxxxxxx>: >> > > >> > > >> > > Hello, >> > > >> > > Looking at final stages of planning / setup for a CEPH Cluster. >> > > >> > > Per a Storage node looking @ >> > > >> > > 2 x SSD OS / Journal >> > > 10 x SATA Disk >> > > >> > > Will have a small Raid 1 Partition for the OS, however not sure if best to > do: >> > > >> > > 5 x Journal Per a SSD >> > >> > Best solution. Will give you the most performance for the OSDs. RAID-1 will > just burn through cycles on the SSDs. >> > >> > SSDs don't fail that often. >> > >> What Wido wrote, but let us know what SSDs you're planning to use. >> >> Because the detailed version of that sentence should read: >> "Well known and tested DC level SSDs whose size/endurance levels are matched > to the workload rarely fail, especially unexpected." >> >> > Wido >> > >> > > 10 x Journal on Raid 1 of two SSD's >> > > >> > > Is the "Performance" increase from splitting 5 Journal's on each SSD worth > the "issue" caused when one SSD goes down? >> > > >> As always, assume at least a node being the failure domain you need to be > able to handle. >> >> Christian >> >> > > Thanks, >> > > Ashley >> > > _______________________________________________ >> > > ceph-users mailing list >> > > ceph-users@xxxxxxxxxxxxxx >> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > _______________________________________________ >> > ceph-users mailing list >> > ceph-users@xxxxxxxxxxxxxx >> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >> > >> >> > > > -- > Christian Balzer Network/Systems Engineer > chibi@xxxxxxx Global OnLine Japan/Rakuten Communications > http://www.gol.com/ > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com -- Klinik-Service Neubrandenburg GmbH Allendestr. 30, 17036 Neubrandenburg Amtsgericht Neubrandenburg, HRB 2457 Geschaeftsfuehrerin: Gudrun Kappich _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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