Re: Unionmount status?

From: Ric Wheeler
Date: Thu Apr 14 2011 - 09:21:46 EST

On 04/14/2011 05:40 AM, Miklos Szeredi wrote:
On Thu, Apr 14, 2011 at 11:32 AM, Michal Suchanek<hramrach@xxxxxxxxxx> wrote:
I guess overlayfs includes the better part of unionmount and achieves
similar level of functionality in much smaller code size and is
actively developed.

This might make it the best candidate for inclusion so far.

It does not (yet?) support NFS which is one of the options commonly
used with union solutions, though.
NFS is supported as a lower (read-only) layer, but not as an upper
(read-write) layer.

I am not that concerned with the state of Val's repo, her intention was to hand off the project cleanly to others and have them drive the code (that hand off was the posting of the patch set). Several people (Ian, David Howells and Al Viro) had been involved with union mounts recently, so we do have reasonable candidates for a hand off.

One of the concerns with unionfs is the duplication of data. Union mounts avoids this with that implementation. That might make unionfs more of a burden for very large file systems, but probably not a concern for many use cases.

The union mount patch set is certainly considerably larger.

Christoph had expressed some concerns about locking that I think it would be good to discuss again as well.


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