Re(2): [SunRescue] a bit OT but...

[Gregory Leblanc]

> -----Original Message-----
> From: tim_hauber at STEV.net [mailto:tim_hauber at STEV.net]
> Sent: Wednesday, March 15, 2000 3:30 PM
> To: rescue at sunhelp.org
> Subject: Re(2): [SunRescue] a bit OT but...
> 
> rescue at sunhelp.org writes:
> >
> >Didn't I hear somewhere that you don't 'need' to reboot to upgrade to
> >Solaris 8?  Or am I wrong?
> >
> >-Jonathan
> 
> Oh goody!, someone invented a kernel that can hand off 
> running processes. 
> Somehow I think that if this is true then someone has 
> re-defined the term
> "reboot"  As far as I know any changes that require replacing 
> or changing
> the kernel always require a reboot, because the kernel lives 
> in memory. 

Yeah, seems nifty, but unlikely.

>  I suppose someone could invent a method of changing the 
> kernel while it
> ran, but it would be an academic exercise on an extremely 
> lightly loaded
> machine, and I imagine the code to monitor exactly where the 
> kernel was
> executing at a given moment in time would require breakpoints 
> built into
> the kernel itself, so you might as well just shut it down and 
> upgrade it. 
> The trend in Linux toward dynamically loaded modules may at 
> some point be
> utilized to make a very upgradeable while running system, but uptimes
> really aren't that big a deal anyway.  uptime before the 
> machine has to be
> brought down, or crashes, is important, and this is the 
> Windows weakness.  
> I don't feel a reboot for upgrade in any way besmirches the 
> quality of the
> machine or the admin. 

Sort of.  I'm going to talk from a Netware vs NT vs RedHat here, because I
haven't done a lot of "upgrades" on Solaris yet.  In the olden days when I
was a netware genuis on NW311 and NW411, any patch I applied just required
unloading some modules, then replacing the files, then reloading the modules
at the worst.  With NT4, any time you update ANYTHING, you have to reboot.
If you change a single IP, you don't have to reboot, but if you add another
IP, or your change 1 of many IPs, that's a reboot.  A hotfix for one of the
huge security holes, that's a reboot.  Netware has gone downhill here with
NW5, a lot of the patches now require reboots.  As for my RedHat upgrades,
basically I grab the packages, run a command that upgrades those packages,
and restart the service.  Kernel upgrades are a little different, but I do
those by hand anyway, and I don't replace the kernel unless it has something
DARN specific that I'm looking for.  Since I've never run any applications
on Netware, it doesn't apply, but upgrades to NT apps often require a
reboot.  

[snip]
> uptime for posterity, and shut it down.  In a growing system 
> things like
> memory very likely need to be upgraded, and in all but the 
> very largest
> configurations that requires a full powerdown.  

Sort of true, the HP deal with "licenses" for processors lets you turn up
capacity on demand, with only your credit card as the tool.

> too much.  Before the upgrade we were getting a few months 
> for uptimes,
> still better than a lot of NT machines.

But a lot worse than some as well.
	Greg