Thanks Janne, It is good to know that moving the devices over to a new class is a safe operation. On Tue, Oct 24, 2023 at 2:16 PM Janne Johansson <icepic.dz@xxxxxxxxx> wrote: > >> The documentation describes that I could set a device class for an OSD >> with >> a command like: >> >> `ceph osd crush set-device-class CLASS OSD_ID [OSD_ID ..]` >> >> Class names can be arbitrary strings like 'big_nvme". Before setting a >> new >> device class to an OSD that already has an assigned device class, should >> use `ceph osd crush rm-device-class ssd osd.XX`. >> > > Yes, you can re-"name" them by removing old class and setting a new one. > > >> Can I proceed to directly remove these OSDs from the current device class >> and assign to a new device class? Should they be moved one by one? What is >> the way to safely protect data from the existing pool that they are mapped >> to? >> >> > Yes, the PGs on them will be misplaced, so if their pool aims to only use > "ssd" > and you re-label them to big-nvme instead, the PGs will look for other > "ssd"-named > OSDs to land on, and move themselves if possible. It is a fairly safe > operation where > they continue to work, but will try to evacuate the PGs which should not > be there. > > Worst case, your planning is wrong, and the "ssd" OSDs can't accept them, > and you > can just undo the relabel and the PGs come back. > > -- > May the most significant bit of your life be positive. > -- Matt Larson, PhD Madison, WI 53705 U.S.A. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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