Ceph » CephFS

I moved elsewhere a directory that had a layout policy set. Later on, next time the mds lost directory policy information, I accidentally run an outdated version of the script to reset policies, and the host on which I ran it froze solid. After it rebooted, I could get it to freeze again running just the set_layout command for the symlink. Adjusting the script to set the policy on the moved dir rather than the symlink that took its place, the problem no longer occurred. Later on, I ran another test and the host did not freeze when I tried to set the policy on the symlink, so it doesn't seem to be 100% reproducible.

Recipe:

cd /mnt/ceph.ko/
mkdir a b
ln -s ../b a/c
cephfs a/c set_layout -u 4194304 -s 4194304 -c 1 -o -1 -p 9 # maybe replace with 0 if you don't have pool #9