[OT] Hard drive recovery

Jacqui caren jacqui.caren at ntlworld.com
Tue Sep 18 15:29:50 BST 2007

David Cantrell wrote:
> So the third time - everyone who got caught out the second time by
> fucked up unreadable tapes :-)

As the original company is now defunct this not exactly giving out
state secrets anymore...

At Cray research we backed  up software dev (SWD) systems religously.
However the backup software used a neat feature ofCray's at the time.
A 4K inode would hold the file if the file were smaller than ~3.5KB.

When someone changed this behaviour the backup software (which did
NOT use the standard FS API and accessed the disk via its own drivers)
assumed the file contents were still in the inode and prompty wrote
~3.5K of nulls for every small file to the backup tapes.
You guessed it - somoene did a system restore on a dev box and
lost the entire machine...

Shit hitting fan just does not cover it.


p.s. It is amazing just how many backup systems out there periodically
write gibberish - and do not have write verify enabled!

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