On Tue, 2013-12-17 at 16:53 +-0000, David Howells wrote: +AD4- It has occurred to me and others that something like BTRFS could be a good fit +AD4- to build an AFS fileserver directly on top of. The question is what facilities +AD4- would be needed from BTRFS to make this work? +AD4- +AD4- So I thought I'd kick off a shopping list+ADs--) +AD4- +AD4- (1) 64-bit data version numbers that increase monotonically with each write. +AD4- +AD4- Yes, this is likely to cause some performance degredation as it introduces +AD4- an ordering over data writes and metadata writes to a file. Maybe writes +AD4- can be batched to improve performance? +AD4- +AD4- (2) Storage for ACLs and AFS UIDs. Having shareable ACLs might also be useful. +AD4- +AD4- Xattrs would likely do for this. +AD4- +AD4- (3) The ability to snapshot a filesystem to make backups and for pushing to +AD4- read-only volume servers. +AD4- +AD4- (4) A 32-bit vnode number and 32-bit vnode uniquifier/generation number. +AD4- +AD4- These don't necessarily have to be stored by BTRFS directly but could +AD4- instead be in a separate database file that gets snapshotted also. +AD4- +AD4- (5) The ability to set the vnode number, vnode uniquifier and data version +AD4- number to specific values. Necessary to clone volumes and restore +AD4- volume dumps. Hmmm, what exactly are vnodes? Could we put them in xattrs? -chris -- 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
