Dear all, By default "ceph-disk" will do the following: # ceph-disk -vvvv prepare --fs-type xfs --cluster ceph -- /dev/sdk DEBUG:ceph-disk:Preparing osd data dir /dev/sdk No block device "/dev/sdk" exists so "ceph-disk" decides a block device is not wanted and makes a directory for an OSD. I think as policy "ceph-disk" should not assume by default, that a non existent target is correct, make a directory for the "disk" type OSD to reside in, and set it up as a "disk" type OSD. Hence I proposed this patch: https://github.com/ceph/ceph/pull/2160 As a second best option I would be happier with an explicit "don’t fail if target is not present and just make a directory at the target". But then you get on to the question of deeper directory structures being handled: The current behavior with deeper directory structures is currently inconsistent as this output shows: # ceph-disk prepare --fs-type xfs --cluster ceph -- /mnt/vdu/vdu Traceback (most recent call last): File "/usr/sbin/ceph-disk", line 2605, in <module> main() File "/usr/sbin/ceph-disk", line 2583, in main args.func(args) File "/usr/sbin/ceph-disk", line 1311, in main_prepare os.mkdir(args.data) OSError: [Errno 2] No such file or directory: '/mnt/vdu/vdu' I think as a third best option would be to only make directories the "--data-dir" parameter is used, but still suffers the deeper directory structures question. I am still unsure if I like the idea of creating directories for deeper directory structures, as again the potential for typos leading to vastly different directory paths with a single misplaced character, and for consistency would rather "ceph-disk" just failed if the target is not available. Although I propose failing fast and clearly with a clear error message when a target does not exist, removing the assumption that all non existent targets are valid and "disk" based OSD's and to try and make an "appropriate" directory, I do see 2 issues with this change: (A) This is a change to the current default behavior so effecting deployment frameworks. (B) This would effect "ceph-deploy" which under some circumstances uses this behavior. I propose the following patch to mitigate side effect (B). https://github.com/ceph/ceph-deploy/pull/224 I see no way to resolve issue (A) in general if my proposal for change is selected. I have discussed this issue with "alfredodeza" on IRC both privately and later on the "ceph-devel" IRC channel and he is "really divided here" hence we decided I would bring this up for discussion on this mailing list. Best regards Owen -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
