[lug] apt-get dist-upgrade errors

[Sean Reifschneider]

On Sun, Jan 07, 2007 at 12:48:51AM -0700, Daniel Webb wrote:
>On Thu, Jan 04, 2007 at 11:45:38AM -0700, Elyse M. Grasso wrote:
>seen the Tummy mirrors hang a few times, although they're the best ones I've
>used (and I've forgotten if they mirror Ubuntu too or just plain Debian).

We have both Ubuntu and Debian mirrors.  We also mirror Nexenta, the
Ubuntu-based distro with OpenSolaris kernel.  We also have a static copy of
the backports.org packages for woody.

>It's hard to be too critical of package mirror maintainers, since they're
>providing a potentially expensive service for free.  It would be nice if apt
>were able to handle mirror problems automatically, though, and it doesn't.

Debian is actually kind of hard to mirror.  Of the sources we mirror
(Fedora, RedHat, CentOS, kernel.org, fedoralegacy, livna), Debian requires
more hand-holding than all of the others combined.  About once every 6
months the source I'm mirroring off of will just stop working and I have to
hunt down a new one, either because of system issues on the source, or it
going away.

However, that shouldn't lead to the mirror hanging.  Just being out of
date.

In our case, I think our mirror has been "up" and stable for the vast
majority of the last several years.  However, that doesn't mean that you'll
always have bandwidth available to reach it.  In the case of our mirror,
available bandwidth is much more of an issue than networking or system
problems I'd guess.

The reason I say this is because we dedicate only 1.5mbps guaranteed of
bandwidth to mirrors.  We scale it based on other bandwidth usage at our
facility up to around 10mbps (soon, possibly up to nearly 30mbps).
However, if a bunch of people are hitting it at the same time as one of our
customers is copying data at 70mbps, mirrors traffic may be scrunched way
back down to 1.5mbps.  Which could appear to some users as hanging or at
least very slow connectivity, I'd guess.

This is one place where yum really wins.  It will detect that a mirror is
hung and switch.  If you aren't happy with that, hit Control-C once and it
will kill the current copy and switch to another source.

>know it's not just my configuration.  apt just hangs a lot.  Sometimes just

I wouldn't say that apt hangs a lot.  Not for me.  I wonder if it's
something more at your end of the network than at the mirror sites?  I
can't remember the last time apt hung on me.  Admittedly, a lot of Debian
systems I install software on are at our facility and we offer gigabit
unmetered access to mirrors.  However, plenty of servers I run are not,

Thanks,
Sean
-- 
 Home is where your source is.  -- Sean Reifschneider, 1999
Sean Reifschneider, Member of Technical Staff <jafo at tummy.com>
tummy.com, ltd. - Linux Consulting since 1995: Ask me about High Availability
      Back off man. I'm a scientist.   http://HackingSociety.org/