On Wed, May 11, 2011 at 10:12:06AM +0200, Bill Allombert wrote: > On Tue, May 10, 2011 at 03:32:24PM -0700, Russ Allbery wrote: > > Carsten Hey <cars...@debian.org> writes: > > > > > Besides "/usr -> /", are symlinks to directories still supported as > > > top-level directories and are there still people using such a setup? > > > If nobody uses this anymore, the policy could be adapted to the year > > > 2011. > > > > Is there any reason *not* to continue supporting them? They can > > definitely save you as a short term measure to work around a bad > > partitioning scheme until one can fix it by reformatting. > > A reason might be that now we have bind mounts which are generally much more > robust than symlinks. That was not the case where this policy was written.
Thanks everyone for your explanations. I've updated the symlinks to be absolute. I am, however, unsure if the policy is the ideal solution today compared with 1998 when the Linux VFS was much more primitive. I am yet to be convinced that the absolute link is better technically. One thing I'm wanting to do (when time allows) is work on merging /usr and / where /usr would become a symlink to /. That link would be "/" or ".." and having it absolute would not be good if you look up the path /chroot/usr/bin/foo since you'll actually get /bin/foo on the host, where the path might not even be valid (it might be /usr/bin/foo). With a relative link it will always work correctly. This is exactly the same issue as the /var/run symlink. Other than the rather special use case for absolute links for top level dirs, I'm not sure that absolute links are preferable to relative. Although chroot environments are a special case, absolute symlinks in the chroot could cause serious problems on the host if a link in the chroot points to somewhere on the host; you might end up using the wrong programs, libraries, or even blowing away a huge chunk of the host's filesystem. I guess from the policy POV this is concerns what we consider to be acceptable practice for a sysadmin. While the policy caters for admins who create symlinks for top-level directories, this practice does not extend to subdirectories--where things would still break. Symlinks can be fragile, and we have much better means to rearrange the filesystem now--and this applies to all the platforms we support, not just Linux. From the POV of packaging, I'd like symlinks to point to a specific place, without ambiguity, and in the context of chroots, a relative link is unambiguous whereas an absolute link changes depending on where we are rooted. Regards, Roger -- .''`. Roger Leigh : :' : Debian GNU/Linux http://people.debian.org/~rleigh/ `. `' Printing on GNU/Linux? http://gutenprint.sourceforge.net/ `- GPG Public Key: 0x25BFB848 Please GPG sign your mail.
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