Ceph » CephFS

Patrick Donnelly wrote:

This is with Nautilus v14.2.1? Can you bump up debugging on the MDS during the event and share the log?

root@m3-3101-422:/etc/ceph# ceph versions {
"mon": {
"ceph version 14.2.1 (d555a9489eb35f84f2e1ef49b77e19da9d113972) nautilus (stable)": 3
},
"mgr": {
"ceph version 14.2.1 (d555a9489eb35f84f2e1ef49b77e19da9d113972) nautilus (stable)": 3
},
"osd": {
"ceph version 14.2.1 (d555a9489eb35f84f2e1ef49b77e19da9d113972) nautilus (stable)": 63
},
"mds": {
"ceph version 14.2.1 (d555a9489eb35f84f2e1ef49b77e19da9d113972) nautilus (stable)": 12
},
"overall": {
"ceph version 14.2.1 (d555a9489eb35f84f2e1ef49b77e19da9d113972) nautilus (stable)": 81
}
}

Edited ceph.conf:

1. https://tracker.ceph.com/issues/39704
   debug mds = 5
   debug mds balancer = 5

Even debug 5 shows nothing when trying to touch a new file while at max. I'll delete all of them and start creating them again:

root@mc-3015-201:/mnt/ceph1# find . type f -delete
root@mc-3015-201:/mnt/ceph1# time parallel -i sh -c "fastrandom | split -d -b2 -a5 - {}" - {0..9}

Here's the log from the active mds on cephfs1; it's large uncompressed so it's a .gz.
https://vault.cs.uwaterloo.ca/s/PFsXSEDqXTSyjdr/download

I don't see anything useful there myself... Any other logs or tests that would help?

the log show you were creating files in root directory. mds never fragment root directory.

Zheng Yan wrote:

the log show you were creating files in root directory. mds never fragment root directory.

I see! That's a difference between the filesystems which I didn't even think about. I just tested with a subdirectory and I could create 1 million files. I guess this can be closed; I may make a PR to update the documentation later.