Hi, I'm running CentOS 6.2 x86_64 as xen guest on a CentOS 5.7 dom0. The host is running 2.6.18-274.7.1.el5xen, the guest 2.6.32-220.2.1.el6.x86_64. Memory for domU is set to 1024 MB and "xm list" shows these 1024 MB. But "free -m" on the guest system shows only 652 MB. When I set up a CentOS 5.x guest with 1024 MB "free -m" shoes 1024 MB. Anyone else seeing this? Any ideas on how to fix it? Cheers, Sebastian
Friday, I moved our servers to a new co-lo facility and ran into an
interesting problem with virtual machines.
I did an orderly shutdown of the CentOS 6.3 host, and it in turn suspends
all the guests. It took about an hour and a half to move and fire up the host.
The guests, being suspended, were then an hour and a half behind and it
seems ntpd does not want to correct more than 1000 seconds of error so it would
not automatically adjust the clocks.
I tried the -g argument which is supposed to override the 1000 second
limit but it did not. I ended up having to manually set the clocks close
enough for ntpd to correct.
Since there is no hardware clock for the virtual machines to use when they
boot, it seems that shutdown and reboot of the virtual machines probably would
not have avoided this.
Any suggestions for addressing this particular scenerio other than having
to manually set a bunch of clocks?
-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-_-
Eskimo North Linux Friendly Internet Access, Shell Accounts, and Hosting.
Knowledgeable human assistance, not telephone trees or script readers.
See our web site: http://www.eskimo.com/ (206) 812-0051 or (800) 246-6874.
On Wed, Jan 2, 2013 at 12:53 AM, Robert Dinse <nanook at eskimo.com> wrote:> > Friday, I moved our servers to a new co-lo facility and ran into an > interesting problem with virtual machines. > > I did an orderly shutdown of the CentOS 6.3 host, and it in turn suspends > all the guests. It took about an hour and a half to move and fire up the host. > > The guests, being suspended, were then an hour and a half behind and it > seems ntpd does not want to correct more than 1000 seconds of error so it would > not automatically adjust the clocks. > > I tried the -g argument which is supposed to override the 1000 second > limit but it did not. I ended up having to manually set the clocks close > enough for ntpd to correct. > > Since there is no hardware clock for the virtual machines to use when they > boot, it seems that shutdown and reboot of the virtual machines probably would > not have avoided this. > > Any suggestions for addressing this particular scenerio other than having > to manually set a bunch of clocks?Maybe related to this bug report: http://bugs.centos.org/view.php?id=5726 Not sure if the "tinker panic 0" trick works or not as a workaround (see note 15092). No one has reported back with success or fail. The bug was filed upstream but was closed as CANTFIX : https://bugzilla.redhat.com/show_bug.cgi?id=821988 Akemi
On Wed, Jan 2, 2013 at 3:29 AM, <sg at cyon.ch> wrote:> Hi, > > I'm running CentOS 6.2 x86_64 as xen guest on a CentOS 5.7 dom0. > The host is running 2.6.18-274.7.1.el5xen, the guest > 2.6.32-220.2.1.el6.x86_64. > > Memory for domU is set to 1024 MB and "xm list" shows these 1024 MB. > But "free -m" on the guest system shows only 652 MB. > When I set up a CentOS 5.x guest with 1024 MB "free -m" shoes 1024 MB. > > Anyone else seeing this? Any ideas on how to fix it?Start out by doing all the updates to both the Hyperviisor and the guest. There have been ongoing improvements to kernels, and to libvirt, and ongoing security updates for numerous packages. You should realy be at CentOS 6.3 and CentOS5.8, respectively: CentOS 6.2 and CentOS 5.7 aren't even available on the main download mirrors, anymore.