Kernel SMP and normal on SMP based processor

[Grzeslaw]

Hello

When I type: the yum update command, the result is following:

root@s74 [~]#  yum list updates
Setting up repositories
Reading repository metadata in from local files
Excluding Packages in global exclude list
Finished
Updated Packages
kernel.i686                              2.6.9-55.0.2.EL        update
kernel-smp.i686                       2.6.9-55.0.2.EL        update

Server has the Xeon processor, so the kernel should be SMP.
My question is: what is the kernel.i686 package ? and can I safely update it? I am affraid that after update, the kernel changed to the version without SMP.

[cooldude7273]

A SMP kernel is only needed if you have more than one processor. That includes dual Xeons, dual core procs, and procs with Hyperthreading. So, if all you have is a single Xeon, with no HyperThreading, and not dual core, you can go with the normal kernel.i686.

If you want some professional help updating your kernel, just let me know. (you have your PMs disabled, so I can't contact you.)

[Grzeslaw]

I know the idea of SMP kernels . I use the Intel(R) Xeon(TM) CPU 2.80GHz on server. I just wondering what do (and can i safely update) the package kernel.i686 when I use the SMP kernel by defaults.

root@s74 [~]# uname -pvr
2.6.9-42.0.10.ELsmp #1 SMP Tue Feb 27 10:11:19 EST 2007 i686

Regards

[cooldude7273]

I'm not sure why you would be using a smp kernel on a single proc server - it's not going to kill it, but it's not needed.

I've never personally used yum to update a kernal as I wouldn't trust yum with something so critical. I've always just used the good old fashioned rpm method with a --force flag to make sure it switches from the smp to non-smp.

[Grzeslaw]

root@s74 [~]# cat /proc/cpuinfo
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Xeon(TM) CPU 2.80GHz
stepping        : 3
cpu MHz         : 2801.725
cache size      : 2048 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 1
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 5
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl cid xtpr
bogomips        : 5603.96

processor       : 1
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Xeon(TM) CPU 2.80GHz
stepping        : 3
cpu MHz         : 2801.725
cache size      : 2048 KB
physical id     : 0
siblings        : 2
core id         : 0
cpu cores       : 1
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 5
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl cid xtpr
bogomips        : 5599.47

processor       : 2
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Xeon(TM) CPU 2.80GHz
stepping        : 3
cpu MHz         : 2801.725
cache size      : 2048 KB
physical id     : 3
siblings        : 2
core id         : 3
cpu cores       : 1
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 5
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl cid xtpr
bogomips        : 5599.61

processor       : 3
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Xeon(TM) CPU 2.80GHz
stepping        : 3
cpu MHz         : 2801.725
cache size      : 2048 KB
physical id     : 3
siblings        : 2
core id         : 3
cpu cores       : 1
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 5
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe lm constant_tsc pni monitor ds_cpl cid xtpr
bogomips        : 5599.63

Isn't a dual xeon ?
So I need SMP or not ?

[cooldude7273]

Yes, you do need SMP.

[Grzeslaw]

okey, but back to begining of the post.: is it safely to update the package kernel.i686 ? and why is it installed for, when i use the smp kernel

[chirpy]

There's not need to install the the single-core kernel, just do the SMP one with:

yum install kernel-smp

[Grzeslaw]

ok, so can I remove the previous kernel kernel.i686 - which yum wont's to update?

[chirpy]

Yes, you can, just be careful when typing

[Grzeslaw]

thank you very mych