Move a mail server

[Lisa Casey]

Hi,

I have a sendmail server running on Redhat Linux 7.2. The load average on this machine occasionally goes quite high, and once before I was advised that the server needed more memory. The motherboard in this computer will not support more than around 750 MEG RAM. 

We purchased a "barebones" system: case, motherboard, cpu, fan & power supply in which we can put 2 GB of memory. My original idea was to just move the hard drive from the old computer to the new. We did this once before successfully when a motherboard crashed. Unfortunately, this time it didn't  work. When I try to  boot the drive in the new system, I get the following message during the boot process:

Kernel panic: No init found. Try passing init=option  to kernel

I've done some googling and here's what I THINK the problem is (feel free to let me know if you think I'm way off base here). I think that the kernel on the radhat drive cannot support the new hardware and  I need to upgrade the kernel. I've never upgraded a kernel on Redhat before.

I found a procedure for upgrading the kernel here: http://www.redhat.com/docs/manuals/linux/RHL-7.2-Manual/custom-guide/kernel.html

I'm not 100% certain what kernel is currently in this machine (I didn't set it up originally). uname -r says 2.4.9-31custom  but in /boot I have a initrd-2.4.7-10.img (so I don't know if the kernel is 2.4.9 or 2.4.7). I also can't figure out where to get a new kernel. I checked the errata for redhat 7.2 on the redhat  site and found several but  every one of them says "File Missing" and there's nothing to click on to download it. Can anyone help me out with this? Considering I'm a novice at kernel upgrading, how likely  might I be to render my system unbootable? That would be a disaster as this is currently our only mail server.

Another thought I had to solve this problem is this. Perhaps I should just install a new hard drive in the new system, install linux on it, then move the user accounts and mailboxes over to the new drive. Does anyone know of a good "how to" for moving from one Sendmail server to another?

Anyone have any thoughts as to which of these two procedures might be best to  solve my problem?

Thanks,

Lisa Casey