Thoughts on undeleting ext3 files

[Bill Gradwohl]

Trying to undelete something is too unreliable. What is reliable is backup,
of course. Home users typically don't have tape drives and end up with
machines that haven't been backed up in months, if ever.

There are a number of "snapshot" mechanisms available on the web and one can
always use rsync via a cron job to "backup" important information even if
it's to the same physical disk drive. 

Having a spare /etc directory, for example, located at /snapshot/thisbox/etc
that is 1 day old would have been a life saver for Mr Rabba. If one has 2
physical machines, then one box can snapshot the other box so that even disk
failures can be anticipated.

We routinely set up servers to snapshot Samba data areas because Windows
users frequently ask for restores. Normally we create a snapshot partition
specifically for the purpose, and usually it is an entire disk drive or RAID
array. For home use, a separate partition on the one and only disk drive in
the box would do nicely.

Snapshots done hourly from 9AM thru 5PM allow an administrator to
conveniently reach back to some time in the past and grab a file as it was
at that time and get the Windows user out of the office. Taking periodic
snapshots of the critical O/S directories is just as simple. Sure beats
doing tape restores, and certainly beats reinstalling an O/S due to a
mistake.

Those snapshots are also space efficient. If a file didn't change during a
particular time interval, then several snapshots of that file are all just
links pointing at the one physical copy of the data. Total snapshot disk
space required is roughly equal to the total amount of data being backed up,
plus the amount of change that occurs during a specific time interval. Even
file deletions are handled properly.

It's therefore quite reasonable to have 2 weeks worth of snapshots captured
at any point in time for lots of sites and the cost is a cheap disk drive or
even just an extra partition at install time. 

-- 
Bill Gradwohl
YCC
(817) 224-9400 x211
www.ycc.com 
SPAMstomper Protected E-mail
www.stomperware.com