I have tried to create a ceph filesystem in a single host, for testing purposes, with the following conf file
[global]
log file = /var/log/ceph/$name.log
pid file = /var/run/ceph/$name.pid
[mon]
mon data = /srv/ceph/mon/$name
[mon.mio]
host = penny
mon addr = 127.0.0.1:6789
[mds]
[mds.mio]
host = penny
[osd]
osd data = /srv/ceph/osd/$name
osd journal = /srv/ceph/osd/$name/journal
osd journal size = 1000 ; journal size, in megabytes
[osd.0]
host = penny
devs = /dev/loop1
/dev/loop1 is formatted with XFS and is actually a file with 500Mbs (although that shouldn't matter much) Everything works pretty much OK, and health shows:
sudo ceph -s
2013-12-12 21:14:44.387240 pg v111: 198 pgs: 198 active+clean; 8730 bytes data, 79237 MB used, 20133 MB / 102 GB avail
2013-12-12 21:14:44.388542 mds e6: 1/1/1 up {0=mio=up:active}
2013-12-12 21:14:44.388605 osd e3: 1 osds: 1 up, 1 in
2013-12-12 21:14:44.388738 log 2013-12-12 21:14:32.739326 osd.0 127.0.0.1:6801/8834 181 : [INF] 2.30 scrub ok
2013-12-12 21:14:44.388922 mon e1: 1 mons at {mio=127.0.0.1:6789/0}
but when I try to mount the filesystem
sudo mount -t ceph penny:/ /mnt/ceph
mount error 5 = Input/output error
Usual answers point to ceph-mds not running, but it's actually working:
root 8771 0.0 0.0 574092 4376 ? Ssl 20:43 0:00 /usr/bin/ceph-mds -i mio -c /etc/ceph/ceph.conf
In fact, I managed to make it work previously using these instructions http://blog.bob.sh/2012/02/basic-ceph-storage-kvm-virtualisation.html verbatim previously, but after I tried again I obtained the same problem. Any idea of what might have failed?
Update as indicated by the comment, dmesg shows a problem
[ 6715.712211] libceph: mon0 [::1]:6789 connection failed
[ 6725.728230] libceph: mon1 127.0.1.1:6789 connection failed
Ensure communication is in place between ceph mds node and client node, (Port 6800 & 6801)