[plug] Back-up using Linux

[Denis Brown]

Greetings.

I would like to implement a back-up solution for a peer-peer Win95
situation.  My initial thoughts are Linux, Samba and some form of backup
software.  The other possibility is NT but... I have sucessfully set up a
Debian box with Samba to allow me to browse across subnets to my other
peer-peer Win sites but haven't done much else with it (Debian) yet so am a
bit "newbie."  Here are some features of the site.  Comments appreciated.

Number of Win95 machines:
Eight of which three have important / high-volume data.
Nature of data:
Several statistical datasets ranging to 40MB in size, some data is
confidential (e.g. medical records or other named data).  Other datasets
totalling about 1 GB, reduced data (non-named, non-confidential) which
change frequently (at least weekly).  Statistical analyses require
considerable time to perform so the intermediate data sets are "valuable"
although they can be reconstructed if necessary.  Sensitive data is encrypted.
Frequency of back-up:
Ideally daily incremental with weekly full backup of data areas.  Rotating
tape (media) scheme.  Possibly also a monthly full backup.
Nature of backup:
Timed, preferably after-hours, with as little operator intervention as
possible (limited to tape changing).  Duplicate tapes to be kept off-site.
System files and application programmes need not be backed up as they can
be freshly loaded in the event of disaster.  presently, files are backed up
using Iomega products by the individual users -- inconvenience, ability to
skip the backup because of pressure of work, etc.
Network:
10BaseT with the possibility of going to 100baseT in future if required for
the three main machines.
Siting:
Linux box, keyboard, monitor, backup device and UPS will be in a locked
(i.e. physically secure) area.
Other "server" functionality:
Nil, although some form of dynamic (active?) virus checking of attached
PC's files would be nice!

Discussion/questions:
One possibility is to implement a distributed storage model -- equip the
Linux box with a large enough hard disk that it can be partitioned for each
major user, so that their sensitive data is always present on the Linux
box, making back-up easier (no need to leave machines running 24 hr/day).
In other words, gget the major users to use a network drive rhther than a
local drive.  The disadvantage appears to be that if the Linux box dies,
those three principal users also go down.  Is "shadowing" a possibility
under W95 and / or Linux -- in other words, can I treat the local machines'
drives as a form of "write-through cache" and have the data redundantly
stored?  If the Linux box toppled for some reason they'd just not have
backup until it came up again.

People's experiences with various back-up devices... what sort of devices
work well (reliably) with Linux?  Any to avoid?

For the monthly full backup, CD-W looks promising for the dataset part --
recall that the opsys and applications can be freshly loaded in a disaster
scenario.  Is this (CD-W) a reasonable thought, or would a tape solution be
better?

Thanks in advance,
Denis