[ceph-users] Re: XFS on RBD on EC painfully slow

Hi Reed, To add to this command by Weiwen: On 28.05.21 13:03, 胡 玮文 wrote: When I migrated from XFS on iSCSI (legacy system, no Ceph) to CephFS a few months ago, I used msrsync [1] and was quite happy with the speed. For your use case, I would start with -p 12 but might experiment with up to -p 24 (as you only have 6C/12T in your CPU). With many small files, you also might want to increase -s from the default 1000. Note that msrsync does not work with the --delete rsync flag. As I was syncing a live system, I ended up with this workflow: - Initial sync with msrsync (something like ./msrsync -p 12 --progress --stats --rsync "-aS --numeric-ids" ...) - Second sync with msrsync (to sync changes during the first sync) - Take old storage off-line for users / read-only - Final rsync with --delete (i.e. rsync -aS --numeric-ids --delete ...) - Mount cephfs at location of old storage, adjust /etc/exports with fsid entries where necessary, turn system back on-line / read-write Cheers Sebastian [1] https://github.com/jbd/msrsync