On Friday 03 June 2011 18:24:41 Arne Jansen wrote: > Hi, > > If no one is already working on it, I'd like to take the Quota lock and > see how far I come. > Let me sketch out in short what I'm planning to do: > > - Quota will be subvolume based. Only the FS-trees and data extents > will be accounted. > - Quota Groups can be defined. Every quota group can comprise any > number of subvolumes. A subvolume can be assigned to any number > of quota groups. > - A Quota Group can account/limit the total amount of space that is > referenced by it and/or the amount of space that is exclusively > referenced (i.e. referenced by no other quota group). > - With this it is possible to define a hierarchical quota that need > not necessarily reflect the filesystem hierarchy. > - It is also possible to decide for each snapshot if it should be > accounted into the parent group. So in a scenario where each > subvolume reflect a user home, it's possible to have some snapshots > accounted to the user and others not (e.g. the ones needed for system > backups). > - Quota information will be stored in new records, possibly in a > separate tree. > - It should be possible to change the Quota config and group > assignments online, though this might need a full re-scan of the fs. > - It does NOT include any kind of user/group (UID/GID) quota. > > Any addenda or arguments why it's impossible or insane welcome.
What's the benefit of this complexity? Why not a more simple quota/reservation per subvolume? The semantics you described, can be achived by user/group quotas too. And we need them anyway. Perhaps this can be implemented together, reusing the code. Then we have the question if user/group quotas are per filesystem or per subvolume. regards, Johannes -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
