[Newbie] ubuntu's update-manager???

[Mario Vukelic]

On Wed, 2006-05-24 at 13:36 -0700, David Armour wrote:
> why does the upgrade-manager require a re-boot 
> on some
> mornings rather than others 

Some stuff on a Unix-like system can only be changed by rebooting. The
prime example is the operating system kernel (i.e., linux as such). It
runs in a special CPU mode, and you can't switch to a different kernel
in a running system.

There are a few other things, but not many. In general, Debian-based
systems like Ubuntu are especially good at updating running systems.
Note however that forced reboots are much less frequent than in Windows.

Regarding your question about running multi-user systems. Such a system
would not run a beta version, and as such would have less updates.
Kernel updates for such a machine would only matter if security fixes
arrive, or required features. Then the sysadmin simply must analyze
his/her needs and make a trade-off decision. Any system that can not
accept outages will have backup servers anyway.