XenServer 6.5 VMs shuting down unexpectedly

[Paulo Machado]

We have a Xenserver 6.5 running two windows server virtual machines. It has always behave without a problem; a few weeks ago, however, the VMs begin to shutdown for no apparent reason - I'm a complet xen novice, so troubleshoting the problem has been really difficult..
Looking at message, audit and xensource logs I did notice an uncommon change in time for some entries, exactly at the time of the last shutdown; the timestamp turns back to the correct time after a few entries.Could anyone help me unserstand xen's logs?

 

[Tobias Kreidl]

Is this a standalone host or in a pool? Is the hardware clock enabled or not? Are you running the server(s) against an NTP server?

Do the VMs get their times from the XenServer or independently?

 

-=Tobias

[Paulo Machado]

Tobias it is the only server of a pool (don't ask me why, it was already like that as far as anyone remembers here). The VMs get their times independently. It is running against an NTP server, but (please, forgive my ignorance) it seens to be the pool itself: xenserver.pool.ntp.org ?

[Tobias Kreidl]

There is no such NTP server as xenserver.pool.ntp.org. If you want to put in a single NTP server that's an ANAME record to several,  and it's accessible from your server, use just pool.ntp.org or perhaps better, a country-based subset, such as us.pool.ntp.org or de.pool.ntp.org, etc.

 

My guess is that you are not synchronizing at all and hence your XenServer times are probably way off from what your VMs are getting set to. You can check NTP offsets with "ntpstat -s" and they should be pretty close to the same standard.

 

BTW, a single, stand-alone host can be seen as being its own pool of sorts.

 

-=Tobias

[Alan Lantz]

Time and Disk space are the two Gotcha's for 6.x XenServers. I'm luck enough to have a time source so 

thats what I use, but without it I would use the one's from ntp.org

 

0.north-america.pool.ntp.org

1.north-america.pool.ntp.org

2.north-america.pool.ntp.org

3.north-america.pool.ntp.org

 

If in North America of course, other regions have the same layout and listed online.

 

http://support.ntp.org/bin/view/Servers/NTPPoolServers

 

 

--Alan--

 

[Tobias Kreidl]

And some of those are just DNS ANAME records, like us.pool.ntp.org, which resolve into multiple IP addresses so that you only need to put in the one entry.

 

-=Tobias

[Alan Lantz]

True, but I like to type. 

 

--Alan--

 

[Paulo Machado]

Thanks, everyone; did the changes, let us see if that solves the mystery

[Tobias Kreidl]

Good -- keep us posted! What's your current NTP time offset?

 

-=Tobias