On 04/20/2015 10:08 PM, Ludwig Nussel wrote:
Jan Engelhardt schrieb:
On Monday 2015-04-20 09:12, Tim Serong wrote:
Not in this case. I'm not talking about directly user-accessible files, I'm talking about ceph OSDs. A ceph OSD is (approximately) a single disk with an xfs/btrfs filesystem on top. The ceph-osd daemon manages everything on this filesystem; objects stored by clients in a ceph cluster map back (somehow, by magic) to files on an OSD, but the client doesn't see them at this level in the stack. Rather, all files on an OSD are are created and owned by the user ceph-osd runs as (presently root, but in future, the unprivileged user "ceph"). In order to be able to hotswap an OSD from one node to another, the UID for ceph thus needs to be the same across all nodes in the cluster.
Ah well. In case the disk is wholly owned by ceph,
mount -o uid=xxx,gid=xxx
will be interesting. Some filesystems support it already, and I remember there were calls to make it an fs-independent VFS feature, though I do not know the current development status.
For years I tried to get such a patch into ext[234]. There's always discussion but in the end nobdy goes ahead and merges the patches. Last time Ted at least agreed that it's easier to do this in the individual filesystems: http://thread.gmane.org/gmane.linux.documentation/4945
Latest version of the patch is three years old: http://thread.gmane.org/gmane.comp.file-systems.ext4/32284
It's quite some effort to rebase and test this all the time so I can't keep up.
Hrm. So, given that's a bust, I'm very, very tempted to just take whatever UID/GID the Debian project end up using, and use that on openSUSE and SLES too. It's apparently likely to be 64045 which is well outside any of our defined ranges. Regards, Tim -- Tim Serong Senior Clustering Engineer SUSE tserong@suse.com -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse-factory+owner@opensuse.org