[nailer]

'Don't tell me you're running a 'stock' kernel and never bothered tuning it for your application, or considered upgrading it.'

Not sure why you've got 'stock' in quotes. Vendor kernels are used by hundres of thousands of servers, each sharing the same bug reports and security updates. There's a massive benefit unless you think you can do those bug reports and security updates better than your OS vendor.

Most custom compiles are by people who don't understand loadable modules or read somethign written before they existed.

[jacquesm]

Ok, point taken, but there are definite advantages to 'rolling your own'.

[forkqueue]

Such as?

Using a vendor-supplied kernel means that there are extremely likely to be other people using most of the same stack as you, many of them on the same hardware. If there are problems, it's likely that other people have noticed the issue, even if the bug hasn't been found, so it's much more likely to get fixed.

If you compile your own kernel (and/or copy of Apache, MySQL etc etc) you're running something unique to you. If you have problems, you're on your own.

If you're paying for Red Hat Enterprise, use the Red Hat Enterprise packages unless there's a good reason not to. If something goes wrong, you can call Red Hat support and have at least a steer in the right direction. Custom-compiling everything just for the sake of it, just to have new 'shiny' stuff is crazy.

[jacquesm]

It's not for the 'new shiny' at all, it's got to do with optimizing your kernel to match your hardware and getting rid of loadable module support in favor of a kernel that has on board exactly that which is needed to operate your system.

A 'stock' kernel has a whole pile of things in it that might be the next remote exploit, by removing such stuff you marginally increase security.

Other things you might need:

   - kernel support for booting from raid filesystems without trickery
   - processor family optimizations
   - maximum number of cores (stock = 8, we run 16 on quite a few machines) 

As for compiling, I do that anyway, it's a small job compared to the number of times that you need to do it. And you're just as much 'on your own' to solve problems, the chances of having them are less though (because the system you are running is considerably leaner).

Second your redhat enterprise solution, that's not what I'm using though on most of our machines (either centos or debian), but that's a good solution too.

[nailer]

Not a big user of software RAID, but AFAIK booting from a metadisk / is still out of the box doable as it was a few years ago:

"- processor family optimizations"

RHEL / CentOS include a variety of kernels precompiled for different CPU architectures.

"- maximum number of cores (stock = 8)"

What distro? RHEL / Centos support far more than that, we've got quite a number of 32 core machines and have a few 64 core boxes in test.