On Monday 06 February 2012 12:56:52 Russell Coker wrote:
On Mon, 6 Feb 2012, Chris Samuel <chris@csamuel.org> wrote:
Also be aware that there will be at least one more backwards incompatible filesystem change to fix the maximum number of hard links to a file in a directory, which is currently low enough to break a number of packages (such as backuppc).
How exactly will such changes be incompatible?
Will they involve setting a flag so the older kernel knows not to mount it? Or will things just break?
In the past they've done it via a flag I believe. With the free space cache they even managed to hit upon a way of doing it that older kernels would ignore and then the cache would get rebuilt when mounting with a kernel that supported it.
On Mon, 6 Feb 2012, Avi Miller <avi.miller@gmail.com> wrote:
df lies, which is why you should run: # btrfs fi df /mount
Thanks, although it would be nice if they had a way of giving output comparable to df so that all the programs which expect df output can just work.
I agree, perhaps that could be done by giving the most pessimistic outcome - say assuming that all chunks on a filesystem with duplicate metadata and data will be written that way. cheers, Chris -- Chris Samuel : http://www.csamuel.org/ : Melbourne, VIC This email may come with a PGP signature as a file. Do not panic. For more info see: http://en.wikipedia.org/wiki/OpenPGP