Re: [rdiff-backup-users] Adding SHA1Digest to existing backup

[Andrew Ferguson]

On Feb 13, 2009, at 6:09 PM, Maarten Bezemer wrote:
> I have a number of rdiff-backup repo's that started quite a while  
> ago. With the current version I'm using, changing (or newly added)  
> files get an extra line in the metadata showing the SHA1 digest of  
> the file.
> But older files that haven't changes in many months do not have this  
> information in the metadata.
>
> Is there a way to have rdiff-backup calculate these hashes for all  
> files currently in the repo (only the current version would be  
> enough; previous versions would just not have the checksum and be  
> fine without it).


There isn't a way to have rdiff-backup to do it. However, it is easy  
to script yourself.

You can generate the SHA1 sums using the openssl command (for example):
$ openssl sha1 /path/to/file

The SHA1 hashes are stored in the mirror_metadata file, which is  
inside the rdiff-backup-data dir, and is simply a (gzip'd) text file.  
Here's an example entry:

File foo
  Type reg
  Size 5
  SHA1Digest 4cbd040533a2f43fc6691d773d510cda70f4126a
  ModTime 1234621688
  Uid 501
  Uname owsla
  Gid 0
  Gname wheel
  Permissions 420

For every entry of "Type reg", without a SHA1Digest line, simply add  
in that line.


Andrew