Switch to a sane packaging and upgrade system

[Dennis Gilmore]

On Thursday 17 January 2008, Bernardo Innocenti wrote:
> C. Scott Ananian wrote:
> > My thoughts are that I would like to write a yum post-install hook
> > which stashed a copy of the RPMs installed to /home/olpc/.rpmcache.  A
> > post-upgrade hook (in olpc-configure) would attempt to reinstall all
> > rpms found in /home/olpc/.rpmcache.  This would address this common
> > use-case (as well as my own: I keep having to re-install emacs).
>
> Yum already downloads all the rpms in /var/lib/yum/<dist>/packages.
> I don't think we need to do anything special.

they get stored in /var/cache/yum/<repo>/packages  though we clean up 
afterwards and dont keep the cache.

> > Volunteers to write the yum hook welcome; the post-upgrade hook is
> > simple.
>
> I don't think it's necessary.  If a yum update
> gets interrupted, there are two possibilities:
>
> 1) the system does not boot any more
>
> 2) the system boots normally
>
>
> In (1), you need to reflash or boot from an older
> snapshot.

> In case (2), you could resume yum normally and it will
> not even need to download any packages.  But you could
> as well do (1).

if you got through installing everything before the interruption there is a 
yum-complete-transaction command that will finish the job.

> So my proposal is: let's extract the checkpointing
> code from olpc-update and use it as a wrapper for
> invoking yum.  "safe-yum"?  It should be much easier
> and safer.
>
> The downsides of using yum remains that it's a real memory
> hog and it will take additional disk space for all the rpms.
> Developers can learn to get around these limitations, but
> automated upgrades would fail very frequently due to these
> problems.
yum cleans up its packages after its done the transaction  how we have it 
configured 

> A very effective solution is reducing the number of packages
> that yum has to deal with.  Fedora is around 11 *thousand*
> packages.  OLPC ships with 450.  Clearly, we could save a
> lot of time and memory by disabling the huge Fedora repository.
>
> Dennis, what do you think?
Having a smaller package set would greatly reduce yums overhead 

We can provide a disabled yum config pointing to a repo of everything. a 
developer can easily enable it.

One thing we MUST do is not point our yum to koji.fedoraproject.org  it needs 
to be pointed at a mirror list not a heavily loaded server. 


Dennis