Portage cache pros and cons

flurix · n00b Joined: 24 Mar 2003 Posts: 26

Hello,

I've been using Gentoo for quite some time and I'm really happy with it. There are a lot
of situations where it is easier to use and to maintain. With distcc & buildpkg mastered
even the compiles aren't so bad. But with portage cache, there's another story.

Every time I do emerge sync, I have to wait for the 'cache update'
to finish. Although it does not matter that much on fast systems, a good old P200
takes forever. Why? That's a question that I would like to discuss.

Here are my thoughs:

* The dependency cache is kept in more than one place:
/var/cache/edb/deps and /usr/portage/metadata/cache. Moreover, metadata/
is updated with each portage sync. I think one cache is enough (either
"hardcoded" in the portage tree, or generated outside of it).
* After each sync, the cache is generated for all the portage tree although
mostly I would like to only emerge something specific because of a recent
security update.
* The cache gets out-of-sync with the tree if something happens to timestamps
in the portage tree so packages fail to compile because of unsatisfied dependencies.
* Some packages (namely net-misc/nut, for example) deside about their dependencies
on the fly and this leads to unexpected behaviour (possibly failed compile).

Having all that said I should conclude that most of these things are just bugs that
may be fixed tomorrow but it seems a bit weird that complex programs are written
just to gain a little or worse in most situations. I propose that while this cache may
be really important to developers, it does little good to system users and at least
there could be some option to disable it.

Currently, I have excluded metadata/cache from rsync's sight and removed both
cache dirs. The dependencies take longer to calculate the first time the ebuild is touched
but it isn't that long and I don't have to wait for the cache update (currently, I sync
the tree manually but am looking forward to tweak the portage do it for me my way :wink:

)

It would really be nice to hear the oppinions of other gentooers on the subject

baxtor · n00b Joined: 05 Mar 2003 Posts: 25 Location: NY

Hi,

Well, this is nice information to know...

Pythonhead · Posted: Wed Jun 18, 2003 12:57 am Post subject:

I'm not really concerned on how long 'emerge sync' takes and I don't have a particularly fast computer (700mhz). I use a 56k modem.

I get on with life and work while doing 'emerge sync'. Why sit there and wait for it? Then again, I only sync when I hear about a new version of portage or a package I need. I use my computer for work 8-12 hours a day without the need to sync more than a few times a month.

Instead of pounding the portage mirrors, I check the CVS update log daily or a few times a week. Also, many of the questions about portage or ebuild errors can be tracked down by glancing at that log:

http://www.gentoo.org/dyn/index-cvs.xml

If any of your points are valid bugs in the code, submit it via bugs.gentoo.org, if they haven't been already.

flurix · n00b Joined: 24 Mar 2003 Posts: 26

I must appologise that my post was something like "the portage cache is a bad thing". It's probably because i've had to sync n times just to see it doesn't help and then the / died.

Now I can say that it is probably a good thing but has some bugs that I'll eighter file or fix.
Thank you for your responses.