On Thu, Mar 26, 2020 at 5:49 AM Frank Schilder <frans@xxxxxx> wrote: > > Some time ago I made a surprising observation. I reorganised a directory structure and needed to move a folder one level up with a command like > > mv A/B/ B > > B contained something like 9TB in very large files. To my surprise, this command didn't return for a couple of minutes and I started to look what was going on. What I discovered was, that the mv command actually performed a full copy with a subsequent remove. I had to wait for several hours for the move to complete. > > I tried to reproduce this today to collect further information. However, this behaviour seems not reproducible. No matter what I try, mv completes almost instantly. > > I was running the original mv on mimic 13.2.2 and retried now with mimic 13.2.8. In addition, there was an OS upgrade from Centos 7.6 to 7.7. I'm using the kernel-ml versions (5.xxx). Only one cephfs mount was present at all times. > > My questions are: > > 1) Was there a change from 13.2.2 to 13.2.8 explaining this? No. > 2) Are there (rare) conditions under which an mv on cephfs becomes a cp+rm? Not as part of CephFS. > 3) Am I seeing ghosts? The only way I can imagine this happening is if you had separate CephFS mounts for cephfs/A/B and cephfs/ and you did the move between them, instead of within the cephfs/ mount. :/ -Greg > > Thanks for clues and best regards, > > ================= > Frank Schilder > AIT Risø Campus > Bygning 109, rum S14 > _______________________________________________ > 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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