> >> > > I need to take 3 of them, 0, 10 and 30, out, is it safe to run out on all 3 > >> > > OSDs at the same time with "ceph osd out 0 10 20" or do I need to take one > >> > > after the other out? > >> > > >> > It is not safe. [...] > >> > What you can do is lower the weight of them to 0.0 and ceph will start > >> > move PGs off them into the others, and when they have 0 PGs, you can > >> > purge them and stop the OSD process and remove the disk. > >> > >> Please note that the original post talks about not yanking OSD drives > >> physically, but about running the "ceph osd out" command. This command > >> is exactly equivalent to reweighing the OSD to zero. > > > >Yes, my bad. I misread the "ceph osd out" as "taking out". You are > >right, telling ceph via "ceph osd out" or reweighting it to zero is > >the same, and both works to make the cluster start emptying those > >OSDs. > > The reason I asked is that several months back I got a off list reply from > a frequent poster on this list, that setting 3 OSDs out at the same time could > give me incomplete PGs as a result. > > But a least now I have 2 saying is OK and 1 saying it's not so thank you > Alexander and Janne. Perhaps this person mistook your question same as I did first, since "removing" or "destroying" or "physically taking out" would all be bad, whereas telling the cluster to stop using them at its earliest convenience and waiting a bit (sometimes days) for it to finish is totally fine. It does depend on how you formulate the "action" verbs I guess. I wanted to make sure it was understood that given a large set of PGs, one or more of them will be exactly on those 3 OSDs, so this PG needs to move away in an orderly fashion, otherwise you will get a broken pool and clients that sooner or later will have stuck IO. -- May the most significant bit of your life be positive. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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