I would not recommend this on Ceph. There was a project where somebody tried to make RADOS amenable to spinning down drives, but I don't think it ever amounted to anything. The issue is just that the OSDs need to do disk writes whenever they get new OSDMaps, there's a lot of random stuff that updates them, and nothing tries to constrain it to restrict writes in mostly-idle clusters. So they wake up constantly to do internal maintenance and heartbeats even if the cluster is idle. If you *really* don't use the data often, the best approach is probably just to turn it all off. You'll need to make sure it turns on fast enough, but if you do a clean shutdown of everything with the right settings applied (you may or may not need things like nodown/noup when changing states, to prevent a lot of map churn) you should be able to make it work. -Greg On Fri, Jan 21, 2022 at 7:40 AM Sebastian Mazza <sebastian@xxxxxxxxxxx> wrote: > > > > > On 21.01.2022, at 14:36, Marc <Marc@xxxxxxxxxxxxxxxxx> wrote: > > > >> > >> I wonder if it is possible to let the HDDs sleep or if the OSD daemons > >> prevent a hold of the spindle motors. Or can it even create some problems > >> for the OSD deamon if the HDD spines down? > >> However, it should be easy to check on a cluster without any load and > >> optimally on a Custer that is not in production, by something like: > >> > > > > From what I can remember was always the test result of spinning down/up drives that it causes more wear/damage then just leaving them spinning. > > > > If you do a spin down / up every 20 minutes or so the wear/damage of the motors is probably a problem. But Christoph stated that the cluster is not used for several days and I don't think one spin up/down per day generates enough spin ups of the spindle motor to be concerned about that. > I have backup storage servers (no ceph) that are running for many years now. The HDDs in this server are spinning only for one or two hours per day and compared to HHDs in productive server that reading and writing 24 / 7, they hardly ever fail. So I wouldn't worry about wear and tear of the motors from spin ups on an archive system that are only used once in a view days. However, it could be that it heavily depends on the drives and I was only extraordinary lucky with all the WD, HGST and Seagate drives in our backup machines. > > Best regards, > Sebastian > _______________________________________________ > 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
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