Rsync of LVM Snapshots copies whole file

[Jamie Lokier]

Paul Slootman wrote:
> If you don't mind that the destination copy is invalid for some time
> (e.g. if it's just used for backup), _and_ you know that data won't be
> moved, only updated at random places, you might try --inplace. That way
> the existing copy is updated, instead of copying the data to a new file.

This reminds me.  When using --sparse to copy an 80GB disk image, I
noticed that rsync sends an awful lot of network data, given that the
image is mostly zeros.  It appeared that --sparse was being applied at
the writing end, not optimising the block checksum transmission at all.

-- Jamie