$ sudo ceph-osd -c /etc/ceph/ceph.conf -i 0 --mkjournal
2015-05-22 11:41:35.335129 7f4c11c03800 -1 journal FileJournal::_open: aio not supported without directio; disabling aio
2015-05-22 11:41:35.335204 7f4c11c03800 -1 created new journal /mnt/journal/ceph-0-journal for object store /var/lib/ceph/osd/ceph-0

SERVICE OSD START

$ sudo start ceph-osd id=0
ceph-osd (ceph/0) stop/pre-start, process 7219

OUTPUT FROM LOGFILE:

/var/log/ceph# tail -f ceph-osd.0.log
2015-05-22 11:16:13.216478 7f78d3c4f800  0 ceph version 0.82 (14085f42ddd0fef4e7e1dc99402d07a8df82c04e), process ceph-osd, pid 5087
2015-05-22 11:16:13.216868 7f78d3c4f800 -1 journal FileJournal::_open: aio not supported without directio; disabling aio
2015-05-22 11:16:13.216903 7f78d3c4f800  1 journal _open /mnt/journal/ceph-0-journal fd 7: 4294967296 bytes, block size 4096 bytes, directio = 0, aio = 0
2015-05-22 11:16:13.216939 7f78d3c4f800  1 journal check: header looks ok
2015-05-22 11:16:13.216957 7f78d3c4f800 -1 created new journal /mnt/journal/ceph-0-journal for object store /var/lib/ceph/osd/ceph-0
2015-05-22 11:41:35.334762 7f4c11c03800  0 ceph version 0.82 (14085f42ddd0fef4e7e1dc99402d07a8df82c04e), process ceph-osd, pid 7137
2015-05-22 11:41:35.335129 7f4c11c03800 -1 journal FileJournal::_open: aio not supported without directio; disabling aio
2015-05-22 11:41:35.335162 7f4c11c03800  1 journal _open /mnt/journal/ceph-0-journal fd 7: 4294967296 bytes, block size 4096 bytes, directio = 0, aio = 0
2015-05-22 11:41:35.335189 7f4c11c03800  1 journal check: header looks ok
2015-05-22 11:41:35.335204 7f4c11c03800 -1 created new journal /mnt/journal/ceph-0-journal for object store /var/lib/ceph/osd/ceph-0