Hmm. On both my plan9port and on a 9front system I find printarenas.c, but
no script. Maybe you are thinking of the script for backup of individual
arenas to file? Yes, that could be a starting point.

Anyway, printarenas.c doesn't look too scary, basically a loop checking all
(or matching) arenas. It seems possible to modify the logic to start at a
specific offset.

Not running fossil at the moment, btw., my main file server is a Linux box,
but I use vac for backup, both at home and at work. Fossil is definitely on
my todo list, although the reported behavior when running out of space is a
bit scary. Do you know why it does not simply block further requests while
checkpointing to venti, or even better, starts a snapshot before it runs
out of space?

On Tue, Dec 12, 2017 at 3:07 PM, Steve Simon <steve@quintile.net> wrote:

> printarenas is a script - it walks through all your arenas at each offset.
>
> You could craft another script that remembers the last arena and offset
> you successfully
> transferred and only send those after that.
>
> I think there is a pattern where you can save the last arena,offset in the
> local
> fossil. Then you could mount the remote venti to check that last
> arena,offset
> that actually arrived and stuck to the disk on the remote site.
>
> On a similar subject I have 10 years of backups from a decomissioned work
> server
> that I need to merge into my home venti one of these days...
>
> -Steve
>
>