Reducing Fedora memory footprint?

[Panu Matilainen]

On Thu, 23 Nov 2006, Leszek Matok wrote:

> Dnia 23-11-2006, czw o godzinie 17:30 +0200, Gilboa Davara napisaÿÿ(a):
>> yum is slower by an order of magnitude than apt-get
>
>> Am I the only one having this problem?
> Well, on this machine, yum -C update takes 14-18 seconds and apt-get
> dist-upgrade takes 9-11 seconds to resolve everything and ask me if I
> want to download.

You'll see a LOT bigger gap in times as the amount of depsolving 
increases, for example fc5 -> fc6 upgrade set. Apt will resolve that in a 
few additional seconds (obviously depending on installed package set, 
computer speed etc) compared to "empty upgrade" whereas yum is going to 
take minutes, even with all metadata and headers locally cached.
Just try timing 'apt-cache unmet' vs 'repoclosure' (from yum-utils) :)

On small sets yum can actually be faster than apt, largely due to the fact 
that apt calculates a full dependency tree of the available package 
universe, whereas yum deals with them in "solve them when needed" basis.

> At this point, yum takes 7 MiB of memory (ps's SZ),
> while apt-get takes 30 MiB (more precisely, apt-shell takes 6,8 to
> resolve dependencies, but 30 when you tell it to commit). I still prefer
> apt for lots of other reasons, but nowadays it's not so much faster and
> doesn't look lighter at all.

Yup, apt isn't *that* light on memory use, due to various reasons:
- when using repomd, it holds the whole primary.xml file in memory for
   a repository at a time, that can consume boatloads of memory (this is
   something I have plans to fix eventually)
- as mentioned earlier, it keeps a precalculated dependency tree of all
   packages in memory at all times

 	- Panu -