Hi The problem is still present in version 17.2.3, thanks for the trick to work around... Regards ----- Mail original ----- > De: "Anh Phan Tuan" <anhphan.net@xxxxxxxxx> > À: "Calhoun, Patrick" <phineas@xxxxxx> > Cc: "Arthur Outhenin-Chalandre" <arthur.outhenin-chalandre@xxxxxxx>, "ceph-users" <ceph-users@xxxxxxx> > Envoyé: Jeudi 11 Août 2022 10:14:17 > Objet: Re: cephadm automatic sizing of WAL/DB on SSD > Hi Patrick, > > I am also facing this bug when deploying a new cluster at the time 16.2.7 > release. > > The bugs relative to the way ceph calculator db_size form give db disk. > > Instead of : slot db size = size of db disk / num slot per disk. > Ceph calculated the value: slot db size = size of db disk (just one disk) / > total number of slots needed (number of osd prepared in that time). > > In your case, you have 2 db disks, It will make the db size only 50% of the > corrected value. > In my case, I have 4 db disks per host, It makes the db size only 25% of > the corrected value. > > This bug happens even when you deploy by batch command. > In that time, I finally used to work around by batch command but only > deploy all osd relative to one db disk a time, in this case ceph calculated > the correct value. > > Cheers, > Anh Phan > > > > On Sat, Jul 30, 2022 at 12:31 AM Calhoun, Patrick <phineas@xxxxxx> wrote: > >> Thanks, Arthur, >> >> I think you are right about that bug looking very similar to what I've >> observed. I'll try to remember to update the list once the fix is merged >> and released and I get a chance to test it. >> >> I'm hoping somebody can comment on what are ceph's current best practices >> for sizing WAL/DB volumes, considering rocksdb levels and compaction. >> >> -Patrick >> >> ________________________________ >> From: Arthur Outhenin-Chalandre <arthur.outhenin-chalandre@xxxxxxx> >> Sent: Friday, July 29, 2022 2:11 AM >> To: ceph-users@xxxxxxx <ceph-users@xxxxxxx> >> Subject: Re: cephadm automatic sizing of WAL/DB on SSD >> >> Hi Patrick, >> >> On 7/28/22 16:22, Calhoun, Patrick wrote: >> > In a new OSD node with 24 hdd (16 TB each) and 2 ssd (1.44 TB each), I'd >> like to have "ceph orch" allocate WAL and DB on the ssd devices. >> > >> > I use the following service spec: >> > spec: >> > data_devices: >> > rotational: 1 >> > size: '14T:' >> > db_devices: >> > rotational: 0 >> > size: '1T:' >> > db_slots: 12 >> > >> > This results in each OSD having a 60GB volume for WAL/DB, which equates >> to 50% total usage in the VG on each ssd, and 50% free. >> > I honestly don't know what size to expect, but exactly 50% of capacity >> makes me suspect this is due to a bug: >> > https://tracker.ceph.com/issues/54541 >> > (In fact, I had run into this bug when specifying block_db_size rather >> than db_slots) >> > >> > Questions: >> > Am I being bit by that bug? >> > Is there a better approach, in general, to my situation? >> > Are DB sizes still governed by the rocksdb tiering? (I thought that >> this was mostly resolved by https://github.com/ceph/ceph/pull/29687 ) >> > If I provision a DB/WAL logical volume size to 61GB, is that >> effectively a 30GB database, and 30GB of extra room for compaction? >> >> I don't use cephadm, but it's maybe related to this regression: >> https://tracker.ceph.com/issues/56031. At list the symptoms looks very >> similar... >> >> Cheers, >> >> -- >> Arthur Outhenin-Chalandre >> _______________________________________________ >> ceph-users mailing list -- ceph-users@xxxxxxx >> To unsubscribe send an email to ceph-users-leave@xxxxxxx >> _______________________________________________ >> ceph-users mailing list -- ceph-users@xxxxxxx >> To unsubscribe send an email to ceph-users-leave@xxxxxxx >> > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx -- Christophe BAILLON Mobile :: +336 16 400 522 Work :: https://eyona.com Twitter :: https://twitter.com/ctof _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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