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Old 09-15-2007, 09:02 AM   #1
Guess
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What does "smp" on the end of a kernel mean?


I have centos 4.5 i386 version installed.

This is the kernel
2.6.9-55.ELsmp

I am trying to install packages for the Oracle Clustered File System OCFS. When I download there i386 version I get:

2.6.9.55-ELsmp

When I go to install it, it does not install correctly.
When I run

rpm -q OCFS* it says all the packages are not installed. When I try to reinstall, it says they are already installed. I am guessing I may have the wrong versions installed?
 
Old 09-15-2007, 09:17 AM   #2
Lenard
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smp==Symmetric multiprocessing

See: http://en.wikipedia.org/wiki/Symmetric_multiprocessing

Quote:
When I go to install it, it does not install correctly.
When I run

rpm -q OCFS* it says all the packages are not installed. When I try to reinstall, it says they are already installed. I am guessing I may have the wrong versions installed?
Posting the exact commands and results would be helpfull, but as a guess try;

rpm -Uvh <the list of packages to re-install here> --force

Example; rpm -Uvh ocfs*.rpm --force

FYI: the correct query to check if packages are installed is: rpm -qa 'kernel*'
 
Old 09-15-2007, 09:19 AM   #3
reddazz
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SMP kernels are meant for systems with two or more processors (or a CPU with multiple cores). If you have a system with those specs then it would be alright to use that kernel.
 
Old 09-15-2007, 10:44 AM   #4
MasterC
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Quote:
Originally Posted by reddazz View Post
SMP kernels are meant for systems with two or more processors (or a CPU with multiple cores). If you have a system with those specs then it would be alright to use that kernel.
With most setups, even if you have a system without those specs, using an smp kernel is ok. You can run into problems with userland applications if you don't have the hardware and are running an smp kernel, but booting the system won't likely be one of those problems.

-Chad
 
Old 09-17-2007, 04:59 AM   #5
salasi
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I believe, these days, kernel.org has stopped supplying smp and non-smp kernels, as the old non-smp kernels are now regarded as having no advantage (and, as has been pointed out, you need an smp-capable kernel to make use of multiple cpu cores).

It is a problem to run a multi-core box with a non-smp kernel (at best, you get lower performance; at worst it crashes, which I don't understand, but has happened to me).

There should not be a problem these days with running an smp kernel on a non-multi-core box, at least by inference. The loss in performance apparently being close to unmeasurable.

OTOH, a 2.6.9 kernel can hardly be classified as anything like up to date these days. I remember a SATA/64 bit bug from back then, but I can't remember anything more relevant. I note you had 2.6.9-55.ELsmp and you are trying to install 2.6.9.55-ELsmp. Is the change from -55 to .55 just a typo?
 
Old 09-17-2007, 05:21 AM   #6
Lenard
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Quote:
Originally Posted by salasi View Post
I believe, these days, kernel.org has stopped supplying smp and non-smp kernels, as the old non-smp kernels are now regarded as having no advantage (and, as has been pointed out, you need an smp-capable kernel to make use of multiple cpu cores).
kernel.org supplies the kernel source for a large number of processors not limited to the Intel family.

Quote:
OTOH, a 2.6.9 kernel can hardly be classified as anything like up to date these days. I remember a SATA/64 bit bug from back then, but I can't remember anything more relevant. I note you had 2.6.9-55.ELsmp and you are trying to install 2.6.9.55-ELsmp. Is the change from -55 to .55 just a typo?
[/quote]

Your comparing Red Delicious apples to Johnathan apples, Red Hat typically keeps the base number (2.6.9) released for the Enterprise family an applies backports, fixes and tweaks from the upstream kernel sources to the kernel updates they release. The OP reported the latest released RHEL4 update 5 kernel which is what CentOS 4.5 is based on.

http://www.redhat.com/security/updat...g/?sc_cid=3093
 
Old 09-19-2007, 12:58 AM   #7
rhaag71
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I just wanted to add my 2 cents (no pun intended).

Quote:
Originally Posted by reddazz View Post
SMP kernels are meant for systems with two or more processors (or a CPU with multiple cores). If you have a system with those specs then it would be alright to use that kernel.
That would also include two logical CPUs as well, such as Intel's Hyperthreading Technology. As HT is not actually two cores or two CPUs, but gives two logical CPUs and reports as two processors according to 'dmesg' and 'cat /proc/cpuinfo'.

I have never had a problem before with single processor setups, but that would be with Ubuntu kernels not RH or CentOS. As for my box running ClarkConnect (soon to be an actual CentOS when I take the time), it does not report using SMP (uname -a or dmesg), and it seems to run fine with the PIII Celeron thats in it, we'll see when I go to CentOS. I did have Ubuntu's kernel with SMP on it before without any obvious problems.
 
  


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