On Fri, Sep 07, 2007 at 11:25:38PM +0100, Stephen Usher wrote: > Nicolas Williams: > > Unfortunately for us at the coal face it's very rare that we can do the > ideal thing. Quotas are part of the problem but the main problem is that > there is currently no way over overcoming the interoperability problems > using the toolset offered by ZFS.
Understood. I'll let the ZFS team answer this. > One way around this for NFSv2/3 clients would be if the ZFS NFS server > could "consolidate" a tree of filesystems so that to the clients it > looks like one filesystem. From the outside the development group this > seems like the 90% solution which would probably take less engineering > effort than the full implementation of a user quota system. I'm not sure > why the OS (outside the ZFS subsystem) would need to know that the > directory tree it's seeing is composed of separate "filesystems" and is > not just one big filesystem. (Unless, of course, there are tape archival > programs which require to save and recreate ZFS sub-filesystems.) It > would also have the added benefit of making df(1) usable again. ;-) Unfortunately there's no way to do this and preserve NFS and POSIX semantics (those preserved by NFS). Think of hard links, to name but one very difficult problem. Just the task of creating a uniform, persistent inode number space out of a multitude of distinct filesystems would be daunting indeed. That is, there are good technical reasons why what you propose is non-trivial. The "why the OS ... would need to know that the directory tree it's seeing is composed of separate "filesystems"" lies in POSIX semantics. And it's as true on the client side as on the server side. The problem you're running into is a limitation of the *client*, not of the server. The quota support you're asking for is to enable a server-side workaround for a client-side problem.. > Believe me when I say that I'd love to use ZFS and would love to be able > to recommend it to everyone as, other than this particular set of > problems, it seems such a great system. My posting on Slashdot was the > culmination of frustration and disappointment after a number of days > trying every trick I could think of to get it working and failing. My view (remember, I'm not in the ZFS team) is that ZFS may simply not be applicable to your use case. That you may find other use cases where it is applicable. If adding quota support is easy, if it's all you need to workaround the automounter issue and if my opinion mattered, then I'd say that we should have ZFS quotas. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
