Ubuntu
linux package

  1. Bug #1338277
  2. Comment #1

Comment 1 for bug 1338277

Revision history for this message
Thiago Martins (martinx) wrote : Re: QEmu 2.0 makes Windows 2008 guests to crash (BSOD)

Guys!

I can confirm that, after disabling KSM, all "guest problems" disappeared!! All Windows 2008 R2 guests are now very stable under QEmu 2.0 but, KSM is disabled.

* Windows 2008 R2 guests running for about 6 hours without any crash *

Workaround - disabling KSM:

---
root@hyper-kvm-1:~# cat /etc/default/qemu-kvm
KSM_ENABLED=0
SLEEP_MILLISECS=200
VHOST_NET_ENABLED=1
KVM_HUGEPAGES=0
---

---
root@hyper-kvm-1:~# cat /sys/kernel/mm/ksm/run
0
---

But, I'm wasting a lot RAM memory, since my guests are clones of each other, I really need QEmu with KSM... :-(

Is there any way to re-enable KSM while preserving system stability? Maybe updating to mainline Kernel? New QEmu version!? Backports?!

-
NOTE:

 Do you guys thinks that this problem might be related to the following BUG:

 QEMU Windows guest unstable after random amount of time:
 https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1322441

 ???
-

Also, Windows 7, when with KSM enabled, crashes during the installation, every time. After disabling KSM, I was able to install and use Windows 7 without any crash, and with SPICE! So, maybe, with Windows 7 ISO CD in hands, this problem might be easy to reproduce, while with Windows 2008 R2, it randomly crashes within ~2 hours...

Cheers!
Thiago