Or run your services/calculations in a VM on Xen that you can snapshot, upgrade the host, and then bring the VMs back up. There are some things you just can't get around (like reboots for core components).
-brandon On Mon, Jun 15, 2009 at 12:16 PM, John Summerfield < [email protected]> wrote: > Dr Andrew C Aitchison wrote: > >> What do other groups do about updating applications and machines >> with long running processes ? >> >> My users run two sorts of long running processes, with different >> problems when it comes to updates. >> >> First, I have users who never log off. Thus applications like >> firefox and pdf viewers will be running when they are updated. >> Some time later these applications may try to load and run plugins >> which have been removed/updated. >> > > I never logoff, and rarely reboot anything between power failures. In my > usage (home, small office), I've never felt the need to update to the latest > kernel just because it's there. I did feel the need last year when CentOS4 > (and RHEL I think) had a series of kernels that locked up after some time on > my hardware. > > Applying updates and keeping on using the system has never caused a problem > that I've noticed, open shared libraries and such are not actually deleted > until every process has closed them. New versions of applications get the > updated libraries. > > Given "binary compatibility" I don't anticipate a problem, except when > there are major updates such as firefox 1,5 to 2.0 or to 3.0. > > If an application crashes, I just restart it. > > >> Second, I have users with long running calculations (often weeks >> or more) which would be interrupted if the machine were rebooted into an >> updated kernel. User-writing code often check-points, so the actual >> calculation time lost is not significant, but calculations in >> commercial packages such as Mathematica and Maple are often less good >> about check-pointing. >> > > Then don't updated them until there is a time available to do so. > Presumably, they're sensibly firewalled and otherwise protected from the > ungodly? > > > > >> How do people balance the disruption of killing user processes >> against the need to update to the latest versions of software ? >> > > Updating software is to prevent a problem you might have. In your case, > updating software is more likely to cause grief than prevent it. I'd not > update until I could take the system out of service. After updating, your > systems might need some QA to ascertain they're still fit for service. > > > > > -- > > Cheers > John > > -- spambait > [email protected] [email protected] > -- Advice > http://webfoot.com/advice/email.top.php > http://www.catb.org/~esr/faqs/smart-questions.html<http://www.catb.org/%7Eesr/faqs/smart-questions.html> > http://support.microsoft.com/kb/555375 > > You cannot reply off-list:-) > -- Brandon Galbraith Mobile: 630.400.6992 FNAL: 630.840.2141
