Metadata restore from Ceph RAODS

[mcassaniti]

I'm using JuiceFS with Ceph RADOS for object storage. This uses the librados library to interact with Ceph. I noticed that metadata backups are written into Ceph but I wasn't sure how to access them. Please note I do not have a RADOS gateway deployed because I would not need it when accessing Ceph directly.

[frostwind]

https://docs.ceph.com/en/reef/man/8/rados/
Maybe some rados command can dump files? Eg rados get name outfile?

[mcassaniti]

This is exactly what I'm looking for. Thank you. To assist the next person:

# The pool used for JuiceFS storage in Ceph
JFS_POOL="juicefs"

# Find the metadata objects
rados --pool="$JFS_POOL" ls | grep meta

# Save a metadata file locally to meta.json.gz
rados --pool="$JFS_POOL" get <OBJECT> meta.json.gz