On 04/16/2015 08:05 PM, Ludwig Nussel wrote:
Jan Engelhardt schrieb:
On Thursday 2015-04-16 10:40, Ludwig Nussel wrote:
Tim Serong schrieb:
On 04/14/2015 03:04 PM, Tim Serong wrote:
A long time ago, there was a thread regarding UID/GID registration (see http://lists.opensuse.org/opensuse-buildservice/2009-05/msg00221.html).
AFAICT the question "how can one register a static UID/GID in the 0-99 range" wasn't answered.
There is no defined process to register uids there and I don't think we should start doing that again.
Context: the ceph project wants to reserve a UID/GID - being a distributed storage cluster, it's best if the UID/GIDs remain static across the whole cluster, and the most straightforward way to do this is to hardcode a UID/GID in a useradd/groupadd invocation in the rpm %pre script.
As long as process credentials are not 64/128-bit UIDs similar to NTSIDs, services ought to cope with different numerical UIDs. NFS made the jump with idmapd, so I am sure ceph can come up with something too. Perhaps even reuse idmapd.
I agree. There are still some use cases where same uids are desirable nevertheless. For example to be able to reuse a file system with data on it on different installations.
That's exactly why the ceph project wants a static UID - so you can easily hot swap a disk from one node in the cluster to another node. There'll be a shim to `chown -R` when necessary (e.g.: when moving a disk between distros), but this naturally slow and expensive and they're hoping to avoid it when swapping disks between hosts running the same distro. There's a bit more discussion on this at https://fedorahosted.org/fpc/ticket/524 (request to reserve static UID for Ceph on Fedora). 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