I made this mistake originally, too…
It’s not real clear in the documentation, but it turns out that if you just initialize your journal drives as GPT, but don’t create the partitions, and then prepare your OSDs with: $ ceph-deploy osd prepare node1:sde:sda (ie, specify the device, not an individual partition) then it will create a new partition (sized according to the osd_journal_size setting under [osd] in ceph.conf), and will link to it by UUID. Regards, Thomas. From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of Scott Laird Sent: Thursday, 22 May 2014 8:19 AM To: ceph-users@lists.ceph.com Subject: [ceph-users] Feature request: stable naming for external journals I recently created a few OSDs with journals on a partitioned SSD. Example: $ ceph-deploy osd prepare v2:sde:sda8 It worked fine at first, but after rebooting, the new OSD failed to start. I discovered that the journal drive had been renamed from /dev/sda to /dev/sdc, so the journal symlink in /var/lib/ceph/osd/ceph-XX no longer pointed to the correct block device. I have a couple requests/suggestions: 1. Make this clearer in the logs. I've seen at least a couple cases where a simple "Unable to open journal" message would have saved me a bunch of time. 2. Consider some method of generating more stable journal names under the hood. I'm using /dev/disk/by-id/... under Ubuntu, but that's probably not generally portable. I've been tempted to put a filesystem on my journal devices, mount it by UUID, and then symlink to a file on the mounted device. It's not as fast, but at least it'd have a stable name. (This was caused by adding an SSD and then moving / onto it; during the reboots needed for migrating /, drive ordering changed several times. It probably wouldn't have happened if I'd started with hardware bought new and dedicated to Ceph) Scott
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