A couple of words on a feature that is as simple in idea as it is huge in impact.
When updating an existing backup copy of a file, Bvckup 2 detects and skips over
unmodified parts, copying just the actual changes.
Disk writes are expensive and being selective with copying quickly pays off when
working with large files that slowly change between the backups.
Here it is in action copying a 10 GB virtual disk
of a just rebooted Windows XP
virtual machine -
Progress so far
Copied 19 MB
out of 10 GB
or just 0.2%
in less than 4 minutes
vs 19 minutes
needed for the full copy.
Here is another example of updating a 256 GB TrueCrypt volume
with work files
and about a day's worth of changes -
Copied 1.8 GB
out of 256 GB
or just 0.7%
in about 53 minutes
vs the 4 hours
that would've needed for the full copy.
Give it a try and see for yourself the difference delta copying makes.