SUMMARY: Recovery after rm *'ing.

From: Ed Sanborn (esanborn@cadence.com)
Date: Mon Apr 15 1991 - 11:18:30 CDT


Thank you for all your replies. I haven't yet seen Norton Utilities for
SysV and since the BSD version hasn't been released yet there isn't really
a great procedure for recovering lost data. If you haven't been doing
backups regularly enough then the following hints should help.

  1. After discovering that you've rm'd some number of files take the
machine the disk is on off the network.

  2. Take steps to insure that files aren't being created as this runs the
risk of overwriting your data. The data is still out there on the disk.
As long as the files aren't too big and/or too fragmented you'll be able to
recover most of your data if conditions under #3 are met.

  3. You will need to come up with unique strings within your files that will
be able to be searched for and hopefully won't be found in a zillion other
files on the disk. Something like the procedure name or module name, etc.

  4. The idea is to use "dd" and the raw partition "rsd0g", for example, to
scan the disk and search for occurences of the string. A buffer is kept of
a set buffer size and blocks of data are saved in files before and after the
occurence. One very rough idea is below. You will need to customize it to
suit your needs. This one will work well for medium size files 30k to 60k or
so. If the file isn't fragmented you should recover alot. The files created
by the captured data should be created on another partition obviously.

Please let me know if you are interested in a copy of the program used.

Take care,

             Ed



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