Joined: Feb. 2007
||Posted: Jan. 24 2008,17:35
|Would seem perhaps extreme to throw out uniofs/aufs architecture altogether if legacy can switch it off.|
Or make that a boot option to turn on unionfs and make "legacy" the default.
|Knoppix has been using aufs since 3.9 - how are they going with that?|
Unionfs is iffy on just about every implementation of it. Go through the FreeBSD changelogs and look how many times it's been added and removed. It's been re-implemented in 6.3, which for all I know means series of patches have been added to minimize some of the scary-frightening-proceed-with-caution warnings in the manpage.
Release note with brief notice of "new and improved" unionfs:
And from the manpage:
THIS FILE SYSTEM TYPE IS NOT YET FULLY SUPPORTED (READ: IT DOESN'T WORK) AND USING IT MAY, IN FACT, DESTROY DATA ON YOUR SYSTEM. USE AT YOUR OWN RISK. BEWARE OF DOG. SLIPPERY WHEN WET.
This code also needs an owner in order to be less dangerous - serious hackers can apply by sending mail to <hackers@FreeBSD.org> and announcing their intent to take it over.
Without whiteout support from the file system backing the upper layer, there is no way that delete and rename operations on lower layer objects can be done. EROFS is returned for this kind of operations along with any others which would make modifications to the lower layer, such as chmod(1).
Running find(1) over a union tree has the side-effect of creating a tree of shadow directories in the upper layer.
The execution is flawed. I love the concept, though.
"It felt kind of like having a pitbull terrier on my rear end."
-- meo (copyright(c)2008, all rights reserved)