Den mån 23 sep. 2024 kl 16:23 skrev Stefan Kooman <stefan@xxxxxx>: > > On 23-09-2024 16:04, Dave Hall wrote: > > Thank you to everybody who has responded to my questions. > > > > At this point I think I am starting to understand. However, I am still > > trying to understand the potential for data loss. > > > > In particular: > > > > - In some ways it seems that as long as there is sufficient OSD capacity > > available the worst that can happen from a bad crush map is poor placement > > and poor performance. Is this correct? > > If you would have a (new) crush rule without any OSD mappings all PGs > for pools that use that rule would go in an inactive state, i.e. > downtime. So when you create a (new) rule you would have to check that > CRUSH can indeed find enough OSDs to comply with the policy you defined. Are you sure? I have asked some pools to use an "impossible" crush rule after creation and the PGs only end up as "misplaced". At creation they might stay inactive until a good place for them can be found, but then you can't write data to it so it is not a "data-loss" scenario really if the pool never started. _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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