On Fri, 21 Dec 2012 12:31:28 +0100
"J. Roeleveld" <jo...@antarean.org> wrote:

> On Friday, December 21, 2012 12:02:34 PM Michał Górny wrote:
> > On Fri, 21 Dec 2012 11:24:45 +0100
> > 
> > "J. Roeleveld" <jo...@antarean.org> wrote:
> > > On Friday, December 21, 2012 09:57:25 AM Michał Górny wrote:
> > > > Just let me know when you have to maintain a lot of such systemd
> > > > and upgrade, say, glibc. Then maybe you'll understand.
> > > 
> > > A shared /usr means I need to update ALL the systems at once.
> > > When /usr is not shared, I can update groups at a time.
> > 
> > Yes, and this is what disqualifies it for the general case. If you
> > can't update one at some point, you can't update the others or it is
> > going to likely get broken in a random manner.
> 
> Yes, but do you want to find out when the entire production environment is 
> down? Or would you rather do the upgrades in steps and only risk having to 
> rebuild a few nodes and have a lower performance during that time?
> There is a big difference between 50% performance and 0%.

Didn't you just state that you *have* to update all at the same time?

> > > To save time, a shared filesystem containing binary packages can easily be
> > > used and this is what I use myself.
> > > I have one VM that is used to rebuild the packages when I want to do an
> > > update and the real host then simply uses the binary packages.
> > > The configuration items needed for emerge are synchronized between the
> > > build system and the actual server.
> > 
> > Wait, wait. So you have introduced even more hackery to get it working?
> > Good to hear. That's really a good reason to support your arguments.
> > 'I got it working with a lot of hackery, so it is a good solution!'
> 
> Please explain, what is hackery about having a single host doing all the 
> compiling for multiple servers?
> The only thing I need to synchronize between the "real" host and the 
> "compile" 
> host is "/etc/portage" and "/var/lib/portage/world"

The hackery is about installing packages partially to local
and partially to shared location. I feel like I'm not following anymore
what actually happens there, not that it is worth my time.

> > > The main reason why I would never share an OS filesystem between multiple
> > > systems is to avoid the situation where a failed upgrade takes down the
> > > entire environment.
> > 
> > And this doesn't happen in your case because...? Because as far as I
> > can see:
> > 
> > 1) failed upgrade in /usr takes down the entire environment,
> > 
> > 2) failed upgrade in / may take down the machine,
> > 
> > 3) failed hackery you're doing to get it all working may have even more
> > unpredictable results.
> > 
> > And yes, I prefer to take down the entire environment and fix it in one
> > step. That sounds much better than trying to get it back up and re-sync
> > all the machines which got into some mid-broken state.
> 
> With shared OS filesystems, that is what you will get.
> With non-shared OS filesystems, the other nodes will keep working.

Aren't we talking about shared OS filesystems *right now*?

-- 
Best regards,
Michał Górny

Attachment: signature.asc
Description: PGP signature

Reply via email to