FC3 upgrade without booting off cd

[Net Llama!]

On Thu, 11 Nov 2004, David Bandel wrote:
> On Thu, 11 Nov 2004 09:55:05 -0500 (EST), Net Llama!
> <netllama at linux-sxs.org> wrote:
> > Yea, but i'd have to wonder how stable or reliable the system would be
> > while all of that was happening.  Hell, its upgrading stuff like glibc and
> > adding udev.  Those aren't trivial changes that won't have some kind of
> > impact.
>
> Well, udev is a POS. I've had to uninstall it on every system I've
> tried to use it on.  I'm either using devfs (still) or the static dev
> files.

So far udev is working fine on the 3 boxes that I have FC3 running (one of
which is a production server used for backups).  Granted this is only a
few days, but i'd imagine that udev either works or doesn't.

> I've never had a problem upgrading glibc on a live system.  You do
> have to know which services to restart (like SSH, Apache, and a few
> others).  But you can do it and still be running the services.  If you
> reboot to upgrade, your services are all down until after the upgrade
> is complete.  In some places I've done upgrades, this is not
> tolerable.  A reboot at the end is barely tolerable, but what could
> amount to hours offline is not.

Yea, i've done glibc upgrades on a live system many times.  But that is
just one of many packages invovled in upgrading to FC3.

> > > This is one of the nice things about Debian upgrades.  They aren't a
> > > .. OK, everything is going down for the next few hours .. deal.  Same
> > > for Gentoo.  You upgrade little by little on a daily or weekly basis
> > > and are always current.
> >
> > Yea, but you still have to reboot for a kernel change.  And if added or
> > removed udev/devfs that would be really scary trying to activate the
> > change on a live system without a reboot.
>
> How long does it take your system to reboot?  A matter of minutes, I
> assume (2-3 max?).  This is a _lot different than being down for hours
> (or even 30 minutes).

Sure, but if your live upgrade goes poorly, you're going to be down for
alot more than 30-90 minutes.

> I run an ISP.  I can afford to reboot a system once in a while (maybe
> even once a day).  But if a system goes down for even 5 minutes (much
> less 30 or more to do an upgrade), the phone calls from irate
> customers delay me even longer.
>
> I don't risk downtimes longer than a reboot.  At least not
> deliberately.  Uptimes are not as important to me as not having
> services go down, or if they do, for _very_ short intervals.

For anyone concerned about uptime as you are, all upgrades should be done
on a test system that mirrors the production system to ensure that the
results are positive.  Anyone doing major upgrades (where major is defined
as changing any package that if broken would result in downtime) on a live
system is taking a fairly significant risk.

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Lonni J Friedman                                netllama at linux-sxs.org
Linux Step-by-step & TyGeMo                  http://netllama.ipfox.com