On Sat, 27 Apr 2019, 18:50 Nikhil R, <nikh.ravin...@gmail.com> wrote:
> Guys, > We now have a total of 105 osd’s on 5 baremetal nodes each hosting 21 > osd’s on HDD which are 7Tb with journals on HDD too. Each journal is about > 5GB > This would imply you've got a separate hdd partition for journals, I don't think there's any value in that and would probabaly be detrimental to performance. > > We expanded our cluster last week and added 1 more node with 21 HDD and > journals on same disk. > Our client i/o is too heavy and we are not able to backfill even 1 thread > during peak hours - incase we backfill during peak hours osd's are crashing > causing undersized pg's and if we have another osd crash we wont be able to > use our cluster due to undersized and recovery pg's. During non-peak we can > just backfill 8-10 pgs. > Due to this our MAX AVAIL is draining out very fast. > How much ram have you got in your nodes? In my experience that's a common reason for crashing OSDs during recovery ops What does your recovery and backfill tuning look like? > We are thinking of adding 2 more baremetal nodes with 21 *7tb osd’s on > HDD and add 50GB SSD Journals for these. > We aim to backfill from the 105 osd’s a bit faster and expect writes of > backfillis coming to these osd’s faster. > Ssd journals would certainly help, just be sure it's a model that performs well with Ceph > > Is this a good viable idea? > Thoughts please? > I'd recommend sharing more detail e.g full spec of the nodes, Ceph version etc. > > -Nikhil > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >
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