On Sun, Nov 16, 2014 at 12:39 AM, Thomas Weyergraf T.Weyergraf@virtfinity.de wrote:
Hi folks,
we (the company i am working for) are running several dozens of virtualisation servers using CentOS 6 + Xen4CentOS as the virtualisation infrastructure.
With the latest versions of all packages installed [1], we see failures in live-migration of stock-CentOS6 HVM guests, leaving a "Domain-unnamed" on the source host, while the migrated guest runs fine on the target host.
Domain-0 0 2048 64 r----- 6791.5 Domain-Unnamed 1 4099 4 --ps-- 94.8
The failure is not consistently reproducable, some guests (of the same type) live-migrate just fine, until eventually some seemingly random guest fails, leaving a "Domain-unnamed" Zombie.
Thanks for this report.
It looks like for some reason xend has asked Xen to shut down the domain, but Xen is saying, "Sorry, can't do that yet." That's why restarting xend and removing things from xenstore don't work: xend is just saying what it sees, and what it sees is a zombie domain that refuses to die. :-)
Do you have a serial port connected to any of your servers? * If so, could you: - Send the output just after you notice a domain in this state - Type "Ctrl-A" three times on the console to switch to Xen, and then type 'q' (And send the resulting output) * If not, could you: - send the output of "xl dmesg" - Run "xl debug-keys q" and again take the output of "xl dmesg"?
Can you also do "ps ax | grep qemu" to check to see if the qemu instance associated with this domain has actually been destroyed, or if it's still around?
Also, have you tried running "xl destroy" on the domain and seeing what happens? xl is stateless, so it can often do things along side of xend. This is not a good idea in general as they can freqently end up stepping on each others' toes; but in this case I think it shouldn't be a problem.
Thanks,
-George