Testing Samba and NFS/AMD inter-action

[Roeland M.J. Meyer]

Hello all,

Some may find this redundant, but this addresses a lot of qustions that
I've been seeing, in the last few months, that were not dealt with, in the
whole. In this message, I am addressing only capabilities, not specific
HOW-TOs. It's more of a WHAT-IT-CAN-DO with a hint of
WHY-YOU-WOULD-WANT-TO. In the near view, treat this as a features test report.

SUMMARY:
The questions were related to sharing NFS mounted file systems and sharing
smbpasswd files across hosts. Most questions originated at sites who had
limited availability of non-production equipment and thus could not
experiment extensively.

The short answers are; 

Samba can mount any file system visible from the host Samba is running on,
including file systems which were mounted, via NFS, from other hosts. The
use of AMD are also tranparent to Samba mounts.

A single smbpasswd file can be shared via NFS mounts and need not be
exclusive to the local host. They can be shared. NFS permissions will take
precedence, thus the smbpasswd file can be on a r-o filesystem. The
'exports' and tcp_wrappers systems are adequate security for NFS mounted fs's.

Performance is irrelevent, in the face of a switched, 100baseTX LAN, on a
small sub-net (240). The LAN is almost faster than the local hard-drive
controller.

BACKGROUND
Last month I lost a major piece of my domain when a 3GB drive failed, due
to over-heating. There were insufficient back-ups (mea culpa, kyrie
eleison). The customer database was devastated, all the new Samba
multi-workgroup sources were gone, half of the web-pages were lost, and the
Internet gateway was down for four days. This happened at the worst time
(Murphy <grrrrr>), during a hardware upgrade of the master NOC workstation
and while a new server was being added. Worse, when bringing the domain up,
in crippled-mode, we had a 30 minute power-outage (thanks PG&E) and I saw
the *only* time when I have *ever* heard of an ext2 filesystem getting
corrupted by an unscheduled power-drop (that possibility is no longer
theoretical, it really did happen), so yet another filesystem (6GB,
backed-up this time<whew>) bites the dust. Like any good engineer, I took
the opportunity to upgrade-revamp some things <grin>.

I took the opportunity to implement a uniform file structure, among the
Linux-based servers, the LAN went from 10base2 to switched 100baseTX, I
added 14GB of disk space, a third server for accounting, cut back to NIS
(from shadows), built a new NOC workstation, and re-organizd the
gateway-customer space. We also installed two APC Smart-UPS 1400's.

All of the filesystems are linked together with NFS/AMD. Samba is used to
share portions out to the WinNTws40SP3 machines. For external shares, those
outside of the domain, we will also be using Samba (I hope) and thereby
eliminiating the need to make NFS externally visible to crack attempts.


_________________________________________________
Morgan Hill Software Company, Inc.
Colorado Springs, CO - Livermore, CA - Morgan Hill, CA
              
Domain Administrator (MHSC2-DOM)
Administrative and Technical contact
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InterNIC Id:	MHSC hostmaster (HM239-ORG)
e-mail:		mailto:hostmaster at mhsc.com
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