D&C GLug - Home Page

[ Date Index ] [ Thread Index ] [ <= Previous by date / thread ] [ Next by date / thread => ]

Re: [LUG] Swap Kernel Without Reboot

 

Neil Williams wrote:
> 
> What happens about fsck as well? Isn't this just going to make it worse
> when fsck finally does run after unscheduled downtime? 

Stop running those legacy filesystems ;)

I agree it doesn't look that useful. I suspect the motivation is 
something like the Linux bios projects, since most machines boot, the 
bios does a full hardware scan and test, then the kernel does pretty 
much the same thing (doh).

On more small servers and desktop this is a minor inconvenience.

I know the old HP K class server I worked on took about 15 minutes to 
finish both hardware and Unix kernel boot diagnostics. Where as minor 
things like rerunning fsck and restarting services were over in seconds. 
Doing the checks once in a Linux bios and then reloading a new kernel 
(when none of the hardware is doing anything important!) sounds plausible.

But for the "real thing", which is kernel and driver upgrades on running 
systems they probably have to code the hardware drivers that way from 
the beginning, so it isn't happening on general purpose hardware any 
time soon.

As the documentation says, the new kernel has to recover the state of 
hardware devices, and whether or not it can do that safely and reliably 
depends on the driver. Read as "don't do this to anything important".

-- 
The Mailing List for the Devon & Cornwall LUG
http://mailman.dclug.org.uk/listinfo/list
FAQ: http://www.dcglug.org.uk/linux_adm/list-faq.html