[tahoe-dev] plans for tahoe-1.3.1

[Brian Warner]

On Tue, 10 Mar 2009 12:47:53 +1100
Andrej Falout <andrej at falout.org> wrote:

> Also, I'm not clear on what 'tahoe backup' does when only a small part of
> the file changes - does it upload only changed blocks, or the whole file?

Unfortunately, it must upload the whole file, even if just a single byte
changes. This will remain true for "tahoe backup" until/unless we implement
efficient large mutable files ("LDMF", as we refer to the design), which is a
big project and a long way off.

The backup tool that Shawn is working on should do much better with small
changes, because it uses rsync signatures and stores deltas instead of only
whole files.

> What happens to the files that are moved/renamed?

They should be handled much better: the file will be passed to the tahoe
client node (over the webapi connection), which will hash it and then
discover that the file is already present in the grid, bypassing the rest of
the work.

cheers,
 -Brian