[TriLUG] Bit rot detection without ZFS/btrfs?

[Randy Barlow]

Hello fellow Linux people,

I've been wearing my tin foil hat a little bit too much lately, and I've  
started to become worried about all the files sitting on my various hard  
drives, bit rotting away.

I am aware that ZFS and btrfs are designed to help with this problem, but  
ZFS has its licensing issues, and btrfs isn't yet "blessed" by the Linux  
elders.

Do any of you use anything to detect file corruption on your disks? I'm  
mostly interested in detection at this point, as I think I can pretty well  
use my backups or off site backups to recover, but I need something to  
tell me when I need to do that.

I've considered writing something homegrown to do this, as it's not  
terribly complicated. I could store a checksum on the FS extended  
attributes, or maybe just in a database of some kind.

If anyone knows of a distro package that can do this, I'd love to hear  
about it. There are some interesting challenges to get past (lots of  
opportunities for false positives, for example when checksumming a file  
that is currently being written to by another process.)

-- 
R