[Apt-cacher-ng-users] acngfs

[Eduard Bloch]

#include <hallo.h>
* Jasper Mackenzie [Tue, Oct 25 2011, 03:30:46PM]:
> Good day,
>  I have been playing with acngfs and have a few questions:
> From the man page it wasn't obvious (to me at least) that the ONLY
> included deb lines should be those to the fuse filesystem mount...

I didn't know this is the case. As far as I know, apt usually ignores
online source if it finds equivalent local sources.

> Anyway, when doing my first dist-upgrade on the machine with
> apt-cacher-ng and using acngfs, I noticed that I couldn't see
> anymore how much needed to be downloaded, a bit of a pain, but
> understandable. If its possible somewhow to get an idea of how much
> is going to be downloaded, that would be great.

I didn't figure out a good way set. The whole think is a kludge and
should be integrated into apt in some sane way.

>  AND, the downloading took an age! Before switching to acngfs it
> should have been ~20meg, so I expect ~20 seconds or so. It took
> ~7minutes.

20meg total or 20meg remaining (including the stuff in /var/cache/apt)?
In the last case, there is a problem... AFAIK apt does not use that
cache (IMHO because it belongs to the online sources, see above) and
gets everything from "local" source.

Actually, all data is fetched at least twice over the local link (for
apt's checksumming and dpkg's work) and if you use apt-listchanges or
apt-listbugs then they will add another two transfers of package data.

Besides of that, there is one real potential performance killer I am
aware of - the internal reads are limited, either by the block size of
fuse or by caller's buffer, and this causes the server to reconnect to
remotes and fetch each part. Now this connection was intended to be used
in keep-alive mode, reused again and again, but I just saw that this
does not work in the current version... looks like a bug needing
investigation.

And for the reuse of /var/cache/apt contents, I think I could add an
option to acngfs to do that where needed.

> one more thing..
>  Is there a command to update all the repos's that apt-cacher-ng is
> tracking, such that I can get cron to do this when I have cheap/free
> bandwidth. (This would make the need to see how much is going to be
> downloaded obsolete...)

This sounds familiar, please have a look at
http://www.unix-ag.uni-kl.de/~bloch/acng/html/howtos.html#mirroring .

This feature needs more testing, I hope to get some feedback soon.

Regards,
Eduard.