[Duplicity-talk] Incremental backup of files with changed data but unchanged timestamp

[Nate Eldredge]

I am using duplicity to make incremental backups of my system.  I have 
some files whose data has changed since the last backup, but whose mtime 
stayed the same.  It looks like `duplicity incremental' ignores files 
whose timestamp has not changed, so it doesn't back up the new data.  Is 
there a way to force duplicity to compare the file with a stored checksum, 
or even to use rdiff unconditionally?  I'd prefer not to have to do a new 
full backup.

I'd consider hacking duplicity myself but it would be helpful to know 
where in the code I should look.

(Before you accuse me of abusing timestamps: it isn't my fault!  I 
crossgraded this Ubuntu system from 32-bit to 64-bit.  It appears that 
some Ubuntu packages have the same timestamps on corresponding files in 
the 32-bit and 64-bit versions.  Presumably the packages were generated at 
the same time, and coincidentally those files were compiled during the 
same second.  So when I replaced the 32-bit package with the 64-bit 
package, I get a different file with the same timestamp.)

I'm using duplicity 0.6.23 (latest from the PPA) on Ubuntu 14.04.

Thanks!

--
Nate Eldredge
address@hidden