I have a very small and quite old hard drive disk, about 32G.
On to this disk I have copied a largish tar file, about 5G.
When I run md5sum to generate a checksum on this file I repeatedly get different results (on the same machine and the same file). This obviously should not happen.
If I repeat the experiment with a much smaller file, as expected the checksum is the same each time. I can only assume that because the large file is spanning most of the disk, and it is an old drive, I am experiencing a lot of read errors on the hard drive - and it needs replacing? Could there be any other good reason for this? Something I can do to fix the problem other than buying a new disk?
Update: sha1sum also produces inconsistent results.