Hi all, I am doing the tracing work in Xen. I run two DomUs, and both have the same built xen 2.6.18.8 kernel. Each domain U has a filesystem image file mounted as root and run X11 GUI mode. I modfiy the kernel source code and direct the two domU logs to remote syslog server via printk/syslog. The problem I found is that multiple domainUs are to some extents time-correlated if both are idle, for example, the crond daemons execute the scripts almost at the same period although the domUs boots at different time. Can someone tell whether there is explicit synchronization done for DomUs in Xen? Why are they synchronized, like some system daemons? Another problem is because I use the kernel ring buffer to cache the log information from kernel, some log in the kernel ring buffer has been wrapped by new log so that some log can''t be written to log file. The default kernel buffer size config is 16KB, and I tried to increase it to 128KB. However, log missing problem is still there. Especially running I/O benchmarks, the trace missing problem is more severe. These tracing log records the I/O activity within the domU kernels, covering read and write paths. Does someone have alternative ideas for this problem. Your answers are appreciated. Alex _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Dear All, I am trying to set vcpu count to the domU which is not showing me desired result using ''xm vcpu-set <domain> <vCPU-count>''. My machine is AMD Opteron 2 core, and have rhel5.3 installed on it. I am running a ubuntu-8 hardy domU and tried to give both vcpu to domU but when I do ''xm vcpu-list'', I see following output Name ID VCPU CPU State CPU Domain-0 0 0 0 r-- 0 Domain-0 1 1 1 r-- 1 ubuntu-8 2 0 1 --- any I tried to add ''vcpu = 2'' in the .cfg file for domU, but was not able to increase the vcpu count for domU to 2. Please suggest if it is possible to give both vcpu to domU and if yes, what is more that need to be done. Thanks for your advice! Regards! Ata E Husain _________________________________________________________________ More than messages–check out the rest of the Windows Live™. http://www.microsoft.com/india/windows/windowslive/ _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Sat, Jun 6, 2009 at 5:50 AM, Lei Ye<leiye.xen@gmail.com> wrote:> The problem I found > is that multiple domainUs are to some extents time-correlated if both are > idle, for example, the crond daemons execute the scripts almost at the same > period although the domUs boots at different time.Why is that a problem? The traditional cron are supposed to run on schedule. So if you have two domUs, same distro, same packages, no customization to cron files, it''s only normal that they execute cron jobs at the same time. If you don''t want them to start at the same time you can start by editing /etc/crontab. An exception is when you have anacron installed, in which case cron execution might depend on system startup time.> Can someone tell whether > there is explicit synchronization done for DomUs in Xen? Why are they > synchronized, like some system daemons?domUs clock are synchronized to dom0 by default. You can change this, but since we''re talking about system clock they should be synchronized anyway. No other synchronizations occur between domUs. -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2009-Jun-06 00:35 UTC
Re: [Xen-users] Increase VCPU count for DomU guest!
On Sat, Jun 6, 2009 at 6:05 AM, Ata Bohra<ata.husain@hotmail.com> wrote:> I tried to add ''vcpu = 2'' in the .cfg file for domUThat should be vcpus=2 -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users