Dear All,

I have changed the number of vCPU from 1 to 4 in a Vsphere console for a virtual machine running RHEL 4.8 but the change is not dedected in OS. The server is still running with 1 CPU. Below are the steps I did to change the number of vCPUs. 1. Powered off the VM -> Edit Settings -> Changed the vCPU number to 4 -> Apply.
2. Powered on the VM

Once the OS came up I checked /proc/cpuinfo still it showed CPU - 1. I am not sure if i am missing some thing... Appreciate any help to resole this issue.

$ cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 26
model name : Intel(R) Xeon(R) CPU E5540 @ 2.53GHz
stepping : 5
cpu MHz : 2525.591
cache size : 8192 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 11
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 nx rdtscp lm constant_tsc pni popcnt
bogomips : 5056.39

$ uname -m
i686
$ getconf WORD_BIT
32
$ cat /etc/redhat-release
Red Hat Enterprise Linux ES release 4 (Nahant Update 8)

With a system that old they probably had a separate SMP kernel. Maybe see what this produces(untested as I don't have a 32-bit (old) system to check).

Thanks a lot for your response syg00.

Please find the details below

$ grep -iE "(nr_cpus|smp)" /boot/config-$(uname -r)
CONFIG_BROKEN_ON_SMP=y
# CONFIG_X86_BIGSMP is not set
# CONFIG_SMP is not set
CONFIG_X86_FIND_SMP_CONFIG=y

I'd reckon you need a SMP kernel - I think that would be ...ELsmp. What does "uname -a" output ?.

I ve installed SMP kernel and it worked like a charm.. Thanks a lot for your advice syg00...