Re: [Nolug] Spam and Virus Protection

On 9 Jul 2003, Ron Johnson wrote:

> > More interesting, the most unreliable piece in our mail system has been
> > the Linux kernel.
>
> How so?

Lots of VM (virtual memory) problems, kswapd using too much CPU and not
freeing file cache memory properly. It's a problem on a system with lots
of file activity (ie mailserver). It would run for a few days then start
thrashing and crap out. There are still some big VM problems in 2.4 with
more than 4gb memory.

Redhat's enterprise kernel (based on 2.4.9) never did work. I tried stock
2.4.20, 2.4.21-pre's, -ac series, -aa series, and tried many patches from
people on the kernel list. Finally settled on compiling the Redhat 9
kernel, which uses a modified rmap VM. It is pretty stable. I think the
rmap VM is what's in 2.5 and going into 2.6. Shortly after that after
many months of complaints and errata releases that didn't fix anything,
redhat released a kernel that fixed most of the VM problems. I'm running
it on the 2nd mailserver, and it appears pretty stable also.

In the process, learned more about the kernel VM than i probably wanted to
know. :)

-ray

-- 
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
Ray DeJean  				       	 http://www.r-a-y.org
Systems Engineer                    Southeastern Louisiana University
IBM Certified Specialist  	      AIX Administration, AIX Support
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=
___________________
Nolug mailing list
nolug@nolug.org