Re: [ceph-users] Bluestore "separate" WAL and DB

I thought I'd pick up on this older thread instead of starting a new one. For the WAL something between 512MB and 2GB should be sufficient as Mark Nelson explained in a different thread. The DB however I'm not certain about at this moment. The general consensus seems to be: "use as much as

Re: [ceph-users] Bluestore "separate" WAL and DB

Bump! i would love the thoughts about this ! On Fri, Sep 8, 2017 at 7:44 AM, Richard Hesketh < richard.hesk...@rd.bbc.co.uk> wrote: > Hi, > > Reading the ceph-users list I'm obviously seeing a lot of people talking > about using bluestore now that Luminous has been released. I note that many >

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?) [and recovery sleep]

I do run with osd_max_backfills and osd_recovery_max_active turned up quite a bit from the defaults, I'm trying for as much recovery throughput as possible. I would hazard a guess that the impact seen from the sleep settings is proportionally much smaller if your other recovery-related

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?) [and recovery sleep]

I'm really glad to hear that it wasn't bluestore! :) It raises another concern though. We didn't expect to see that much of a slowdown with the current throttle settings. An order of magnitude slowdown in recovery performance isn't ideal at all. I wonder if we could improve things

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?) [and recovery sleep]

Yeah, that hit the nail on the head. Significantly reducing/eliminating the recovery sleep times increases the recovery speed back up (and beyond!) the levels I was expecting to see - recovery is almost an order of magnitude faster now. Thanks for educating me about those changes! Rich On

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?)

Hi Richard, Regarding recovery speed, have you looked through any of Neha's results on recovery sleep testing earlier this summer? https://www.spinics.net/lists/ceph-devel/msg37665.html She tested bluestore and filestore under a couple of different scenarios. The gist of it is that time to

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?)

Thanks for the links. That does seem to largely confirm that what I haven't horribly misunderstood anything and I've not been doing anything obviously wrong while converting my disks; there's no point specifying separate WAL/DB partitions if they're going to go on the same device, throw as much

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?)

Take a look at these which should answer at least some of your questions. http://ceph.com/community/new-luminous-bluestore/ http://ceph.com/planet/understanding-bluestore-cephs-new-storage-backend/ On Mon, Sep 11, 2017 at 8:45 PM, Richard Hesketh wrote: > On

Re: [ceph-users] Bluestore "separate" WAL and DB (and WAL/DB size?)

On 08/09/17 11:44, Richard Hesketh wrote: > Hi, > > Reading the ceph-users list I'm obviously seeing a lot of people talking > about using bluestore now that Luminous has been released. I note that many > users seem to be under the impression that they need separate block devices > for the