VMware FAQ

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Five Minute System Hang

Symptom: System hangs that occur randomly, but always last exactly 5 minutes.

Check to see whether or not you are using the HPET timer (on the host system).

# grep -i hpet dmesg 
ACPI: HPET (v001 DELL   PE_SC3   0x00000001 DELL 0x00000001) @ 0x00000000000f2cad
ACPI: HPET id: 0x8086a201 base: 0xfed00000
time.c: Using 14.318180 MHz HPET timer.
time.c: Using HPET/TSC based timekeeping.

If so, you may have an HPET problem. HPET is a hardware timer found on newer computers.

A useful thread can be found here: http://communities.vmware.com/thread/77895?tstart=0&start=15

Doctor, doctor, it hurts when I use HPET. Ok...then...don't use it.

To disable HPET, add nohpet as kernel parameter. Your /etc/grub.conf should look kinda, sorta, like (in part):

title CentOS (2.6.9-67.0.7.ELsmp)
        root (hd0,0)
        kernel /vmlinuz-2.6.9-67.0.7.ELsmp ro root=LABEL=/ nohpet
        initrd /initrd-2.6.9-67.0.7.ELsmp.img

Notice the nohpet keyword above?

BTW, this isn't really a VMware problem, but VMware tends to trigger the bug more often than "regular" system workloads.

Guest System Clock Running Too Fast

If your guest system is running *way* too fast, especially on Quad core systems (imagine how fast time would be running on a petascale system like Blue Waters).

Edit your /etc/vmware/config file on your host system and add the following lines:

host.cpukHz = "2400000"
host.noTSC = "TRUE"
ptsc.noTSC = "TRUE"

Of course, plug in the correct cpukHz value for your system.

See also: VMware Knowledgebase Article 1591

A seriously useful primer on why one should not take time for granted.

Poor Sound Quality in a Linux Guest

Symptom: Jittery or choppy sound in a linux guest system, especially if sound is ok in a Windows guest on the same host.

Edit the vmx configuration file of your guest system, and add the following two lines:

pciSound.DAC1InterruptsPerSec = "0"
pciSound.DAC2InterruptsPerSec = "0"

This is totally undocumented. I dare you, double dare you, to find anything on the vmware site about this. But it works. I could guess as to what it's doing, but I suppose that it could also have the side effect of melting your L2 cache. Use at your own risk.

Virtual Monitor Resolutions in Windows Guest

VMware Tools, when installed in Windows XP guests, does not add widescreen monitor resolutions.

To add, say, 1680x1050 as an available resolution, use regedit to add a new resolution.x key at this location:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\vmx_svga\Device0 

Details are described in VMware Knowledgebase Article 1003

Hardware Support for Virtualization

To see if your CPU supports hardware virtualization, look on the "flags" line of /proc/cpuinfo.

  • On Intel CPUs, the flag is vmx
  • On AMD CPUs, the flag is svm

If the flag is missing, you do not have hardware support.

Other Useful Stuff

All the VMX parameters are listed here:

http://sanbarrow.com/vmx.html

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