Installation guide

Important
These instructions are for AMD revision F cpus only.
If the CPU lacks the constant_tsc bit, disable all power management features (BZ #513138). Each
system has several timers it uses to keep time. The TSC is not stable on the host, which is sometimes
caused by cpufreq changes, deep C state, or migration to a host with a faster TSC. Deep C sleep
states can stop the TSC. To prevent the kernel using deep C states append
"processor.max_cstate=1" to the kernel boot options in the grub.conf file on the host:
term Red Hat Enterprise Linux Server (2.6.18-159.el5)
root (hd0,0)
kernel /vmlinuz-2.6.18-159.el5 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
processor.max_cstate=1
Disable cpufreq (only necessary on hosts without the constant_tsc) by editing the
/etc/sysconfig/cpuspeed configuration file and change the MIN_SPEED and MAX_SPEED
variables to the highest frequency available. Valid limits can be found in the
/sys/devices/system/cpu/cpu*/cpufreq/scaling_available_frequencies files.
Usin g t h e p ara- virt u aliz ed clo ck wit h Red Hat En t erp rise Lin u x gu est s
For certain Red Hat Enterprise Linux guests, additional kernel parameters are required. These
parameters can be set by appending them to the end of the /kernel line in the /boot/grub/grub.conf file
of the guest.
The table below lists versions of Red Hat Enterprise Linux and the parameters required for guests on
systems without a constant Time Stamp Counter.
Red Hat En t erp rise Lin u x Ad d it io n al g u est kern el p aramet ers
5.4 AMD64/Intel 64 with the para-virtualized
clock
Additional parameters are not required
5.4 AMD64/Intel 64 without the para-virtualized
clock
notsc lpj=n
5.4 x86 with the para-virtualized clock Additional parameters are not required
5.4 x86 without the para-virtualized clock clocksource=acpi_pm lpj=n
5.3 AMD64/Intel 64 notsc
5.3 x86 clocksource=acpi_pm
4.8 AMD64/Intel 64 notsc
4.8 x86 clock=pmtmr
3.9 AMD64/Intel 64 Additional parameters are not required
3.9 x86 Additional parameters are not required
Red Hat En t erp rise Lin ux 5 Virt ualizat ion Guid e
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