roger@roger-ceph:/etc/ceph$ more ceph.conf
[osd]
	osd journal size = 1000
	filestore xattr use omap = true

	# Execute $ hostname to retrieve the name of your host,
	# and replace {hostname} with the name of your host.
	# For the monitor, replace {ip-address} with the IP
	# address of your host.

[mon.a]

	host = roger-ceph
	mon addr = 10.1.10.20:6789

[osd.0]
	host = roger-ceph

[osd.1]
	host = roger-ceph

[mds.a]
	host = roger-ceph

roger@roger-ceph:/var/lib/ceph/osd$ ls -la
total 16
drwxr-xr-x 4 root root 4096 Oct  2 12:32 .
drwxr-xr-x 6 root root 4096 Oct  2 12:31 ..
drwxr-xr-x 2 root root 4096 Oct  2 12:32 ceph-0
drwxr-xr-x 2 root root 4096 Oct  2 12:32 ceph-1

root@roger-ceph:/etc/ceph# mkcephfs -a -c /etc/ceph/ceph.conf -k ceph.keyring
temp dir is /tmp/mkcephfs.dCS0oSukn3
preparing monmap in /tmp/mkcephfs.dCS0oSukn3/monmap
/usr/bin/monmaptool --create --clobber --add a 10.1.10.20:6789 --print /tmp/mkcephfs.dCS0oSukn3/monmap
/usr/bin/monmaptool: monmap file /tmp/mkcephfs.dCS0oSukn3/monmap
/usr/bin/monmaptool: generated fsid 4df0e2b2-3960-4bd8-b224-86f5cd880ff3
epoch 0
fsid 4df0e2b2-3960-4bd8-b224-86f5cd880ff3
last_changed 2012-10-02 12:53:42.567799
created 2012-10-02 12:53:42.567799
0: 10.1.10.20:6789/0 mon.a
/usr/bin/monmaptool: writing epoch 0 to /tmp/mkcephfs.dCS0oSukn3/monmap (1 monitors)
=== osd.0 ===
2012-10-02 12:53:42.614942 7f467f611780 must specify '--osd-data=foo' data path
2012-10-02 12:53:42.615334 7f467f611780 usage: ceph-osd -i osdid [--osd-data=path] [--osd-journal=path] [--mkfs] [--mkjournal] [--convert-filestore]
2012-10-02 12:53:42.615724 7f467f611780    --debug_osd N   set debug level (e.g. 10)
--conf/-c        Read configuration from the given configuration file
-d               Run in foreground, log to stderr.
-f               Run in foreground, log to usual location.
--id/-i          set ID portion of my name
--name/-n        set name (TYPE.ID)
--version        show version and quit

   --debug_ms N
        set message debug level (e.g. 1)
failed: '/sbin/mkcephfs -d /tmp/mkcephfs.dCS0oSukn3 --init-daemon osd.0'