[monit-dev] symbolic links in filesystem check doesn't works

[Sergey B Kirpichev]

Hello,

Right now we have very uninformative message like
--->8---
[MSK Mar 16 23:18:05] error    : 'homefs' unable to read filesystem
/dev/dm-5 state
--->8---
when the path for "check filesystem" clause IS a symlink AND the target
of this symlink IS NOT in /etc/mtab.  For example:
--->8---
$ grep home /etc/mtab
/dev/mapper/squeeze-home /home ext3 rw 0 0
$ ls -l /dev/mapper/squeeze-home
lrwxrwxrwx 1 root root 7 Mar 16 23:11 /dev/mapper/squeeze-home -> ../dm-5
$ mount | grep home
/dev/mapper/squeeze-home on /home type ext3 (rw)
--->8---

What you would like to suggest in this situation?  This
seems to be more "a bug", not "a feature".

The trivial "fix" is to report more fine-graned errors in this case.  But
looks like an access to filesystem device via symlink (introduced in
5.0) is supposed to work as well as for direct pointing to the
device file.  Isn't?

Related monit conf snippet:
--->8---
 check filesystem homefs with path /dev/mapper/squeeze-home
   if failed permission 660 then unmonitor
   if failed uid root then unmonitor
   if failed gid disk then unmonitor
   if space usage > 80% for 5 times within 15 cycles then alert
   if space usage > 99% then stop
   if inode usage > 30000 then alert
   if inode usage > 99% then stop
--->8---

See also:
http://bugs.debian.org/617259
http://lists.nongnu.org/archive/html/monit-general/2010-05/msg00020.html