On Wed, 2005-05-18 at 20:15 +0200, Enrico Scholz wrote:
This CLONE_NEWNS and (related) 'mount --bind' operations are
not very
well supported by the kernel:
* there does not exist a way to enter an already existing namespace; so,
e.g. two different ssh sessions would have different /tmp directories
Right, but that shouldn't be a problem since you can share data via your
home directory or a specially-designated scratch area, etc.
* namespaces are causing problems with automounters
Sounds like a regular bug; I don't think automounters would come into
play for /tmp anyways?
* 'mount --bind' does not accept/honor options like
'noatime' or 'noexec'
(which could be usefully e.g. to mount $HOME/tmp as /tmp). Patches are
existing but responsible kernel maintainer refuses to apply them :(
noexec's always been virtually useless. noatime is useful, but not so
much that it would be a showstopper for CLONE_NEWNS, in my opinion.
* CLONE_NEWNS + 'mount --bind' are not very well documented
and it is
often unclear whether strange behavior is expected or not. E.g. it may
happen that '/' and '/..' are pointing to different inodes; dunno if
this is wanted or not.
Hm, so it might confuse tools? I'd imagine most tools out there recurse
downwards into a path and so won't hit that issue, but it is something
to watch out for.