Reading for area during rsync

[Jamie Lokier]

Wayne Davison wrote:
> > There is an area I would like to rsync with remote site. Is there a
> > problem reading/writing to that area during the time rsync is in
> > progress?
> 
> Rsync should handle changes fairly well, but it is not perfect.  If the
> currently-active file is changed while it is being transferred, rsync
> can create a version on the destination that is a combination of the old
> and new data (if that is what was read by the sender),
...
> but the next
> transfer should fix the bogus file (since the mtime should have been
> updated by the change that occurred on the sending side after the
> transfer started).

But this won't work if the change that occurred on the sending side
after the transfer started happens within the same second, and the
mtimes have only one second resolution, will it?

That's quite likely, if the file is reasonably small and the first
rsync managed to send a mixture of old and new content - that implies
the other program changing the file was running at nearly the same time.

-- Jamie