Bug #24284
closedcephfs: allow prohibiting user snapshots in CephFS
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Description
Since snapshots can be used to circumvent (accidentally or not) the quotas as snapshot file data that has since been modified or deleted does not count towards the quota.
(This may already be implemented?)
Alternatively, we could also just start counting the snapshot data but this seems non-trivial?
Updated by Patrick Donnelly almost 6 years ago
- Related to Feature #11154: snapshots: support rstats better added
Updated by Patrick Donnelly almost 6 years ago
Zheng Yan wrote:
change default of mds_snap_max_uid to 0
Okay, but we should enforce that as a file system option (`ceph fs set`) so it's consistently enforced by all MDS and visible to clients.
Updated by Greg Farnum almost 6 years ago
We should actually discuss what kind of interface admins want. Dan van der Ster certainly has thoughts; others might as well.
eg an "fs set" max uid is better than nothing, but they might prefer it be set for subtrees similarly to layouts? So a privileged user can grant permission to an unprivileged user to snapshot their directory on a case-by-case basis or something.
Updated by Dan van der Ster almost 6 years ago
change default of mds_snap_max_uid to 0
Use-cases such as Manila let the users mount with root so this will be ineffective.
My humble opinion about this topic is to document the behaviour (limitation) until incremental snapshot usage can be accounted properly by the quota.
We can document that "quota" refers to space used by current head, and e.g. "snapquota" is a snapshot aware quota still to be developed...
Updated by Zheng Yan almost 6 years ago
- Status changed from New to Fix Under Review
Updated by Patrick Donnelly almost 6 years ago
- Status changed from Fix Under Review to Pending Backport
Updated by Patrick Donnelly almost 6 years ago
- Copied to Backport #24705: mimic: cephfs: allow prohibiting user snapshots in CephFS added
Updated by Nathan Cutler almost 6 years ago
- Status changed from Pending Backport to Resolved