similar to: VMWare - 5.2 Update - Kernel Best Practices

I read http://bugs.centos.org/view.php?id=2189 Summary: CentOS is not getting optimal performance in a virtualized environment and on slow cpus but I am not sure I understand the current best practice. Your thoughts would be appreciated. Options as I see them: 1. Run kernel-vm-2.6.18-53.1.4.el5 with clocksource=pit until the excellent CentOS team builds the latest kernel into a VM kernel

OK, so I need to bring up a new vm and was wondering what the state of vm kernels for centos. I have read this http://bugs.centos.org/view.php?id=2189about the tick divider but it wasn't clear what the best step forward is for centos 5.1 was, i usually ran with the clocksource=pit option and it looked like that and the divider option caused a problem. I have in the past compiled my own but

I'm running VMware Server 1.0.6 on a CentOS 5.2 host and am having some clock difficulties. Host OS is x86_64 running on 1.9 GHz AMD Sempron, nVidia chipset. Guest OS's are 32-bit FreeBSD (clock works fine after disabling ACPI, setting the clock source to the PIT, and running the guest tools), WinXP (unknown clock status), and i686 CentOS 5.2 (here is the problem). I've tried pretty

Hi all, If you are using the kernel divider= option in your vmware quest, you are probably aware of the bugs reported at: https://bugzilla.redhat.com/show_bug.cgi?id=315471 Someone @redhat "confirmed" the fix is in the test kernel -92. I tried it but it seems to have the same problem as before - when used with clocksource=pit, it hangs on bootup. Wonder if some of you can test this

Hi everyone: Just a follow up on the fast clock issue: "Can you double-check that 'cat /sys/devices/system/cpu/cpu0/cpufreq/cpuinfo_max_freq' outputs the same number as your 'cpuKHZ' setting in your config.ini file?" There is no cpufreq directory under /sys/devices/system/cpu/cpu0; all I see is "cache" (dir), "crash_notes" (a file) and

Hi everyone, I have been struggling with having the clock of Linux VM's (including CentOS 4.6 and 5.1) running very fast under VMWare, no matter what I have tried. My platform: - AMD Turion X2 TL-60 - AMD 690 chipset with integrated Radeon x1250 (probably doesn't concern in this case) - Windows Vista Ultimate x64, all Windows Update patches loaded (no SP1 yet) - 4GB RAM - VMWare

Under 4.6, we recompiled the kernel with HZ=100 for improved time-keeping in VMware guests. I've read about the backporting of the divider patch into RHEL/CentOS 4.7, but it sounds like it also comes with some bugs. I have been unable to determine the current status of the divider option in the latest 4.7 kernel update. I have experimented with "divider=10" and it works with no major

Howdy, I am having time-drift issues on my CentOS VM. I had referred to following documentation: http://wiki.centos.org/TipsAndTricks/VMWare_Server , however it didn't help. I used kickstart for creating this VM and I am listing important steps in ref to timekeeping issue. Any comments or suggestion would be appreciated. - CS. ------------------- # For EL5 virtual machines, Append the

On Debian Squeeze (2.6.32-5) running Xen 4.0, I have created 2 Ubuntu Lucid Lynx (Ubuntu 10.04) vms. The vms, in a stress test, pass a large file between them via nfs file sharing. A previous entry in this forum helped to establish that some ethernet cards improve VM IO performance. However, our box installed with better intel nics is still rebooting under heavy VM IO loads. The kernel call

On Thu, 30 Sep 2010 14:02:34 +0800, gang.wei@intel.com wrote: > I am the original developer of HPET broadcast code. > > First of all, to disable HPET broadcast, no additional patch is required. > Please simply add option "cpuidle=off" or "max_cstate=1" at xen cmdline in > /boot/grub/grub.conf. > > Second, I noticed that the issue just occur on

Hello gurus, I have two physical xen hosts and when I migrate a domU from one host to another, I get many of this error from domU kernel: clocksource/0: Time went backwards: delta=-3536123661 shadow=686019823475 offset=281887188 Sometimes domU time stalls and network stops working, but other times it gets working again. The two hosts are using different platform timer source:

Hi, Sometimes, seemingly randomly, long-running Xen domains, using clocksource xen, have their clock shift by ~3000 or ~36000 seconds, often with the dom0 complaining about clocksource tsc. The number changes if the hypervisor is explicitly told to use clocksource=pit, but it still happens. It doesn''t seem to be particularly hardware-specific. See also http://bugs.debian.org/599161 I

Hey all, I was watching some logs on a domU today and i suddenly noticed that the timestamps were off by something on the order of 47 seconds. I was surprised because *I don''t* run independent wall clocks. I checked some other domUs and the "drift" was also very close to that of the first domU. I also checked another dom0, Here the domUs were "only" out of sync by

After upgrading to 4.7 x86_64 on all our boxes (from 4.6), we have 3 VMware Server 1.0.5 hosts that are unstable. Sometimes they spontaneously reboot, other times they freeze and require a hard reset. Under 4.6, they were rock solid. Failures tend to be associated with a guest start-up event, but are often at random times as well. There is no useful evidence in either the vmware or messages log

Hello, I was thinking of creating a wiki page about Xen clocksources and timekeeping.. including dom0, PV guests and HVM guests. Dan and Jeremy: You guys might have some ideas for this page.. please let me know your thoughts :) Subjects to cover: - Xen hypervisor clocksources (hpet, acpi_pm, pit) - Xen dom0 clocksource, ntpd, etc - Xen PV guest clocksources, independent_wallclock, ntpd,

Hi there, I am getting very low throughput (around 0.29Mbps) while running netperf benchmark for guest to guest communication on a single physical host. To analyse where the time is spent in hypervisor I wanna use profiling. Please help me choosing good profiler according to my requirments. Should it be better in my case, Xentrace, gprof, xenoprof  or Oprofile. Is it possible to use some vtune

Hi there, I am getting very low throughput (around 0.29Mbps) while running netperf benchmark for guest to guest communication on a single physical host. To analyse where the time is spent in hypervisor I wanna use profiling. Please help me choosing good profiler according to my requirments. Should it be better in my case, Xentrace, gprof, xenoprof  or Oprofile. Is it possible to use some vtune

Hi, I have two installs of Xen 4.0.1 on Debian squeeze dom0s that occasionally skew the time by 3000 seconds. It is always 3000 seconds and it always affects all guests. Depending on the kernels in the guests they will say: tp0 kernel: [9339489.266542] Clocksource tsc unstable (delta = -2999660317697 ns) or perhaps the kernel doesn''t notice but ntpd does: ls0 ntpd[15009]:

Hi, I am running CentOS 5.3 32bit as a VirtualBox 3.0.0 guest running on Windows XP. The Windows host CPU usage is constantly at 50% although the CentOS guest is completely idle (i.e. 0.00 load average). I know this is a common problem related to the 1000Hz frequency that the CentOS kernel runs at. With previous versions of CentOS, I used the kernel-vm package [1] and it solved my problem.

Convert VMI timer to use clock events, making it properly able to use the NO_HZ infrastructure. On UP systems, with no local APIC, we just continue to route these events through the PIT. On systems with a local APIC, or SMP, we provide a single source interrupt chip which creates the local timer IRQ. It actually gets delivered by the APIC hardware, but we don't want to use the same local