Tool for RADOS import/export pool to file
To assist with CephFS disaster recovery, provide the ability to dump an entire pool (the cephfs metadata pool) to a file, and subsequently restore that to an empty pool. This should include all attrs and omaps as well as object data.
This should come with a test that stops a running filesystem, dumps the pool, wipes the pool, restores it, and checks that filesystem comes up again cleanly as if nothing happened.
I expect some issuing of requests in parallel will be needed here to get a sensible level of throughput.
Clearly this is only practical for pools containing somewhat small amounts of metadata: should probably try to make it clear in any docs that this is not meant to be a general purpose way of backing things up!
Possible extension: optionally stream backup to another RADOS pool (or another ceph cluster) instead of a file.
#2 Updated by John Spray about 4 years ago
David: check out what I've done so far on wip-9964, just today I refactored the objectstore-tool code so that we can use the same import/export format for "rados export" dumps. Very happy to hand this over if you're already in progress. I haven't familiarized myself so far with what we'll have to do to get snapshots properly handled in the import/export.