Kernel upgrade - SMP/Hugemem question
 

I've got a server only running the single cpu kernel. I am going to be upgrading it today to the multi-processor kernel (going from 2.6.9-5.EL to kernel-smp-2.6.9-78.0.8.EL.) My question is, the user is planning on maxing out the RAM in this box in the near future (32gigs) which means I will need the hugemem kernel, correct? The only thing I see on RHN is the hugemem-devel package. I had thought there was a kernel-hugememsmp available. How do I install hugemem using just the devel rpm?

Hi -

The "hugemem kernel" is for 32-bit CPUs/32-bit OS's.

If you've got a 64-bit CPU, then you don't need it/don't want it:

http://www.linuxquestions.org/questi...-x8664-438262/

If you *don't* have a 64-bit CPU ... then why not?

'Hope that helps .. PSM

anomie - the Redhat link doesn't give any idea about what the "hugemem" kernel is ... or why it might be a bad idea.

I was originally going to object that we didn't even know if the op had Redhat ... until I noticed the cryptic reference to "RHN" (Red Hat Network, rhn.redhat.com).

But again - if you *can* go to a 64-bit CPU, then you *should* go to 64-bit.

Otherwise, if you're required to stick with 32-bits (for any number of perfectly good reasons), you should consider "hugemem" *only* as a last resort. It adds an extra level of indirection to your memory addressing, and an extra level of complexity to the OS.

IMHO .. PSM

@paulsm4: IMO, the KB article speaks pretty closely to OP's situation. (Except that we don't know which arch / RHEL version he has.) If the info is not useful, he is welcome to ignore it. ;)

@epoh: If you're still unable to locate the kernel you need, you might double check your channels and/or contact RH support.

I don't think RH even offer the hugemem on EL5 - probably for all the reasons above.
If you are on EL4 (considering how old that kernel is) you should probably be able to get it.

Thank you guys. This server is running the x64 smp kernel now. RHEL4, btw. The upgrade to the latest smp went flawlessly. :)