Odd permissions problem

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I've just added a few entries to my disklist and am getting errors like
the following, during amcheck:

    ERROR: athena: [could not access /srv/samba/netlogon
    (/srv/samba/netlogon): Permission denied]
    
    ERROR: athena: [could not access /srv/samba/install
    (/srv/samba/install): Permission denied]

This is strange, because other entries, such as /root and /etc have been
backed-up correctly for many months.  This is a Debian system where
AMANDA uses user 'backup', which is a member of user 'disk' - this
should allow it to backup all local disks without further privileges.

/srv/samba, /root and /etc are all on the same partition, /dev/sda1:

    # ls -l /dev/sda1
    brw-rw----  1 root disk 8, 1 Jun 15 18:26 /dev/sda1

Various permissions:

(For working entries in disklist)

    # ls -ld /root
    drwxr-x---  15 root root 4096 Dec 14 14:31 /root

    # ls -ld /etc 
    drwxr-xr-x  85 root root 4096 Dec 14 14:38 /etc

(For non-working entries in disklist)

    # ls -ld /srv
    drwxr-xr-x  3 root root      4096 Nov 28 10:39 /srv

    # ls -ld /srv/samba
    drwxr-s---  10 root everyone 4096 Nov 21 10:38 /srv/samba

    # ls -ld /srv/samba/install/
    drwxr-s---  5 root everyone  4096 Nov 15 10:01 /srv/samba/install/

    # ls -ld /srv/samba/netlogon/
    drwxr-s---  3 root everyone  4096 Dec 14 09:08 /srv/samba/netlogon/

If I make '/srv/samba' chmod-ed to 755, then the permissions errors go
away.  HOWEVER, I don't want to do that, since there are good reasons
for that directory having the permissions it does.

Why is this directory not visible to the AMANDA process, given that the
AMANDA user is part of group 'disk' and that should give it access to
those partitions?  The '/root/' partition is only (technically) visible
to the root user, yet AMANDA is able to correctly back this up.

Ideas/hints?

Dave.
- -- 
Dave Ewart
davee AT ceu.ox.ac DOT uk
Computing Manager, Cancer Epidemiology Unit
Cancer Research UK / Oxford University
PGP: CC70 1883 BD92 E665 B840 118B 6E94 2CFD 694D E370
Get key from http://www.ceu.ox.ac.uk/~davee/davee-ceu-ox-ac-uk.asc
N 51.7518, W 1.2016
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