On Fri, Feb 26, 2010 at 8:51 PM, Robert LeBlanc <robert@xxxxxxxxxxxxx> wrote: > First off, thanks for the great work on btrfs. I've been trying to > follow the development for some time and now that Debian has > everything in Squeeze, I've been playing around with btrfs. > > I would like to implement btrfs on a large file server that we are > currently using ACLs, user and group quotas and LVM snapshots. While > LVM is nice, it is just choking with as many snapshots as we have and > we need more. I took part of the EXT4 file system and copied it over > to a new partition to play with and was able to convert to btrfs > without problems. ACLs worked just fine which is great news. > > I went to look at the quotas and repquota said that the mount point > doesn't have quotas enabled. I then searched for documentation about > quotas and it was pretty sparse. The only thing that I've found talked > about setting a quota for a subvolume by number of blocks. When I > toyed with ZFS, it had a similar quota system and from what I remember > reading, the devs were getting pressured to implement a quota system > like the previous file systems. > > One thing I'm not sure how it will work is grace period and soft > quotas. It sure would be nice to have this feature with btrfs. The > same applies to checkquota were the owner can be e-mailed. Right now > we have one file system for home directories with user quotas and > another file system for group space with group quotas. We take > snapshots of these file systems and present them to the users as a > directory which Windows interprets as a Shadow Volume copy. > > I thought it would be nice to have one btrfs file system and then > create two subvolumes with appropriate user or group quotas. I would > be able to snap the two subvolumes much like I do now. Since btrfs > does not snapshot subvolumes when a parent is snapped, if I have to > create a separate subvolume for each user or group I can see this > getting very hairy to manage when we have nearly a thousand users and > groups. Have the two subvolumes would give me great flexability to > reallocate space quickly. > > Any insight would be helpful. I can't wait for btrfs to be stable, it > got lots of great potential. > Another thing that I tried was to set a subvolume to a specified size, but it changes the root and all other subvolumes to the same size. I can understand how having subvolumes of differing sizes would be beneficial, much like multiple logical volumes in an LVM volume group. I fail to see the benefit of having a btrfs root fs that is less than the disk or partition as the space can't be used for anything else. I hope I'm just doing something wrong here. Thanks, Robert LeBlanc Life Sciences & Undergraduate Education Computer Support Brigham Young University -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
