[CentOS-virt] VMWare - 5.2 Update - Kernel Best Practices

John Thomas

gmane-2006-04-16 at jt-socal.com
Sun Jun 29 20:15:26 UTC 2008

Johnny Hughes wrote:
> One thing to make sure of if your clock is running fast is to get the 
> correct setting for this in your vmx file for the VM:
> host.cpukHz =
> See this link for more info:
> http://blog.autoedification.com/2006/11/vmware-guest-clock-runs-fast.html
I suspect (please clarify if I am wrong) you mean the /etc/vmware/config 
file, not the vmx file.  The blog article suggests /etc/vmware/config.

> Note:  if you do not have the command cpufreq-info you can get it by 
> installing cpufreq-utils with this command:
> yum install cpufreq-utils
After installing cpufreq-utils, "cpufreq-info" produced, "no or unknown 
cpufreq driver is active on this CPU".  I, through the notes in the 
above blog article, found /proc/cpuinfo had this:
processor       : 0
vendor_id       : GenuineIntel
cpu family      : 15
model           : 4
model name      : Intel(R) Pentium(R) 4 CPU 3.00GHz
stepping        : 1
cpu MHz         : 2995.211
cache size      : 1024 KB
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 
constant_tsc up pni monitor ds_cpl cid xtpr
bogomips        : 5992.20

> Then set the value based on the above article, then time might not run 
> as fast.
I am not sure if I should use:
host.cpukHz = 3000000
host.cpukHz = 2995211

I have tried both.  Neither seems to work.  My current solution, is to 
run a script once per hour that pauses for two seconds, then sets the 
clock back one second.  The vmware time sync brings the guest clock 
current if it gets behind from the script.

Are you able to think deep enough to figure out if I should set the 
host.cpukHz above or below the above range to see if that would slow 
down the guest clock?  I wonder if I should even try that.

> Thanks,
> Johnny Hughes
Thank you Johnny.  I very much appreciate your time.

John Thomas

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