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 <[email protected]> wrote: > > > > > On 21.01.2022, at 14:36, Marc <[email protected]> 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 -- [email protected] > To unsubscribe send an email to [email protected] > _______________________________________________ ceph-users mailing list -- [email protected] To unsubscribe send an email to [email protected]
