"spontaneous" permissions changes

Hi all, I have a strange situation I wish someone could help me with. This is the setup:

- Virtual machine running the latest VM under ESXi
- VM has one processor, 2 GB RAM, 1 GB swap
- Ubuntu 8.04 LTS
- The virtual host runs only this VM
- Virtual host connects to a Lefthand Networks (now HP) SAN through 1 GB copper ethernet and iSCSI
- VM has a 1 TB volume from the SAN that looks like a SCSI drive to Linux (/dev/sdc)
- sdc is formatted as one big ext3 partition (sdc1)
- sdc1 is exported both as an NFS resource and a SMB share (via Samba)
- Authentication is Kerberos and authorization is local, if that matters

The permissions on that partition's mount point, usually 755, changed suddenly to 400. I have looked 
at sudo logs, root's and all admins' history files and I can find no evidence of someone changing 
those permissions or of tampering with the logs.

Physical access to the box requires the right keycard; logon (ssh) access to the box is restricted 
to sysadmins and support personel only; the root password is a 32 char long random string that lives 
in an encrypted repository on my iPod Touch. There are only 2 people, myself included, with full 
sudo rights; there are another 5 people with sudo rights to a number of administration things 
including chmod.

This is a state university and it happened on the first day of classes.

My questions:

- Did I look everywhere I should be looking to find evidence of foul play?
- Does anyone know of anything in this setup that could trigger a seemingly spontaneous permissions 
change like that?

Thanks,

-- 
Yuri Csapo
Academic Computing & Networking
Colorado School of Mines
CT-256
Phone:  (303) 273-3503
Fax:      (303) 273-3475
Email:   [email protected]

Please use the following link to open a service request:
http://helpdesk.mines.edu
===========================================
With a PC, I always felt limited
by the software available.
On Unix, I am limited only by my knowledge.
--Peter J. Schoenster

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