On Fri, Oct 6, 2017 at 6:56 PM, Alfredo Deza <adeza@xxxxxxxxxx> wrote: > Hi, > > Now that ceph-volume is part of the Luminous release, we've been able > to provide filestore support for LVM-based OSDs. We are making use of > LVM's powerful mechanisms to store metadata which allows the process > to no longer rely on UDEV and GPT labels (unlike ceph-disk). > > Bluestore support should be the next step for `ceph-volume lvm`, and > while that is planned we are thinking of ways to improve the current > caveats (like OSDs not coming up) for clusters that have deployed OSDs > with ceph-disk. > > --- New clusters --- > The `ceph-volume lvm` deployment is straightforward (currently > supported in ceph-ansible), but there isn't support for plain disks > (with partitions) currently, like there is with ceph-disk. > > Is there a pressing interest in supporting plain disks with > partitions? Or only supporting LVM-based OSDs fine? > > --- Existing clusters --- > Migration to ceph-volume, even with plain disk support means > re-creating the OSD from scratch, which would end up moving data. > There is no way to make a GPT/ceph-disk OSD become a ceph-volume one > without starting from scratch. > > A temporary workaround would be to provide a way for existing OSDs to > be brought up without UDEV and ceph-disk, by creating logic in > ceph-volume that could load them with systemd directly. This wouldn't > make them lvm-based, nor it would mean there is direct support for > them, just a temporary workaround to make them start without UDEV and > ceph-disk. > > I'm interested in what current users might look for here,: is it fine > to provide this workaround if the issues are that problematic? Or is > it OK to plan a migration towards ceph-volume OSDs? Without fully understanding the technical details and plans, it will be hard to answer this. In general, I wouldn't plan to recreate all OSDs. In our case, we don't currently plan to recreate FileStore OSDs as Bluestore after the Luminous upgrade, as that would be too much work. *New* OSDs will be created the *new* way (is that ceph-disk bluestore? ceph-volume lvm bluestore??) It wouldn't be nice if we created new OSDs today with ceph-disk bluestore, then have to recreate all those with ceph-volume bluestore in a few months. Disks/servers have a ~5 year lifetime, and we want to format OSDs exactly once. I'd hope those OSDs remain bootable for the upcoming releases. (ceph-disk activation works reliably enough here -- just don't remove the existing functionality and we'll be happy). -- dan > > -Alfredo > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
 |