Re: [CentOS-virt] tick divider bugs
On Mon, May 5, 2008 at 11:06 AM, Allen Tsang [EMAIL PROTECTED] wrote: By Paravirtualization, I mean the installation of tools or guest additions type packages, which present virtual interfaces to the guest OS. So in VMware, a component of this would mean setting ethernet0.virtualDev = vmxnet, and having the tools modules pre-installed. A fully virtualized OS for VMware would support all that crap. Let's call these paravirtualized drivers ;), because the system itself is fully virtualized under VMWare and VirtualBox, that's why they can run unmodified operating systems. I know of tru's efforts and others on this front and I really appreciate the knowledge they have brought to the table, but I feel that it's about time that some dedicated entity step in and 'solve' this problem Can you concretely define the problem, and your proposed solution? I am not sure what you are aiming for, and what Tru's images are missing that you are looking for. One man cannot keep such a beast up to date; it needs to be a dedicated effort or project. I think Tru is doing a great job this far. The thing is that we could make a project out of any problem, but that in practice all work is done by one or a few dedicated people. Look at the i586 project: a lot of people say they need CentOS-5 for i586, some people volunteer, some people insist on creating a subproject for this, but in practice nothing happens until someone single-handedly gets the effort going. To me, it seems best to send suggestions to Tru if something is missing. If you want to create something different, write a proposal and send it to this list (if it is related to virtualization, -devel otherwise). Take care, Daniel ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] tick divider bugs
Allen Tsang wrote: Also just to review, clocksource=acpi_pm should be used in conjunction with the tools.synctime = true flag in your vmx file. The combination of the two settings prevents time from going into the future from too many ticks, and synctime corrects slow clocks, which leads to a much, much better clock sync. That (clocksource=acpi_pm) is ONLY the best method if your clock is running SLOWER than normal .. and in fact, a clocksource=pit is probably the best solution for a clock that is running FASTER than normal. If the clock is running FASTER than normal, also getting the max frequency (host.cpukHz) set per these instructions is important: http://blog.autoedification.com/2006/11/vmware-guest-clock-runs-fast.html The /proc/ location in that article is not correct for centos4 or centos5, but you can probably get the correct info for frequency most of the time from /proc/cpuinfo, dmesg, or dmidecode. We'll have to wait until someone figures out a clever way to tie VM clock ticks to a multiplexed physical clock source; until then, clocksync will always be a problem without a complete solution (read up on it). This is as close as it gets! There is a potential fix in the Real Time Kernel () that Red Hat has released as part of their beta MRG release in that it might the support tickless option. I have not had time to look at this solution yet, but the kernel SRPM is here if someone wants to: ftp://ftp.redhat.com/pub/redhat/linux/beta/MRG/RHEL-5/src/ snip Thanks, Johnny Hughes signature.asc Description: OpenPGP digital signature ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] tick divider bugs
Allen Tsang wrote on Mon, 5 May 2008 13:23:26 -0400: Last time I checked, this was a CentOS mailing list. My god, I suggested you actually *read* what's there. You obviously didn't. Please spare me your half-educated guesswork in the future. How is that an unrelated topic? Just read! Good night, EOT. Kai -- Kai Schätzl, Berlin, Germany Get your web at Conactive Internet Services: http://www.conactive.com ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
Re: [CentOS-virt] tick divider bugs
On Mon, May 5, 2008 at 10:39 AM, Allen Tsang [EMAIL PROTECTED] wrote: I've tried almost everything else under the sun with a number of test VMs on our ESX setup, and the best combination of low idle load and accurate timekeeping was achieved using that combination of settings. Yes, ntpd is off. Feel free to give it a shot; I don't take credit for it, I found notes about this on the CentOS bug tracker (http://bugs.centos.org/view.php?id=2189). Like other fine folks have mentioned on this list (much to their amusement likely, now), clocksource=pit is nice, but it doesn't work with divider=10 and hangs on boot. As you can see in that bug tracker, we have spent a lot of time to come up with 100Hz kernels, kernel-vm. These kernels do not have problems with clocksource=pit. Until this bug is eliminated upstream, I think kernel-vm offered by CentOS may be the best solution (shameless advertisement). I just hope it won't take long for the upstream developers to find a fix for the problem associated with the divider= option. Akemi / toracat ___ CentOS-virt mailing list CentOS-virt@centos.org http://lists.centos.org/mailman/listinfo/centos-virt
