On 11/13/19 2:42 AM, Gregory Farnum wrote:
On Tue, Nov 12, 2019 at 6:39 AM Toby Darling <toby@mrc-lmb.cam.ac.uk> wrote:
Hi Folks
I'm writing a backup/sync process for our ceph cluster. The process takes a snapshot of the system that's being backed up and rsync's from that to another ceph cluster
I was hoping to use the snapshot xattrs to verify a successful backup by comparing ceph.dir.rbytes and ceph.dir.rentries between the snapshot and backup target.
However, while files added to the source directory after the snapshot is taken don't appear in the snapshot, ceph.dir.rbytes and ceph.dir.rctime are updated in the xattrs of both.
I don't remember for sure, but I think you're falling victim to rstat propagation being lazy here, and metadata in snapshots being somewhat delayed. Can you try doing a sync before you take the snapshot and see if that changes the behavior? -Greg
yes, rstats in snapshot are not reliable. you'd better to another method to verify your backup. Yan, Zheng
$ fallocate -l 1K test1
$ getfattr -n ceph.dir.rbytes . # file: . ceph.dir.rbytes="1024"
$ mkdir .snap/testsnap
$ fallocate -l 2K test2
$ getfattr -n ceph.dir.rbytes . .snap/testsnap # file: . ceph.dir.rbytes="3072"
# file: .snap/testsnap ceph.dir.rbytes="3072"
$ getfattr -n ceph.dir.rctime . .snap/testsnap # file: . ceph.dir.rctime="1573558448.09736131125"
# file: .snap/testsnap ceph.dir.rctime="1573558448.09736131125"
$ tree -a --si . .snap . |-- [1.0k] test1 `-- [2.0k] test2 .snap `-- [3.1k] testsnap `-- [1.0k] test1
1 directory, 3 files
Have I misunderstood? Is this expected behaviour?
Cheers Toby -- Toby Darling, Scientific Computing (2N249) MRC Laboratory of Molecular Biology Francis Crick Avenue Cambridge Biomedical Campus Cambridge CB2 0QH Phone 01223 267070 _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io