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I'm running 5 VMs on my XenServer 5.5 host:

  • 2x CentOS 5.5
  • 3x Windows-based (SBS 2008, Windows 2003, Windows XP)

Both Linux servers crash at random on a monthly or so basis (not at the same time either). A reboot fixes the issue, however after checking the dmesg log, I found:

device-mapper: uevent: version 1.0.3
device-mapper: ioctl: 4.11.5-ioctl (2007-12-12) initialised:
device-mapper: dm-raid45: initialized v0.2594l
EXT3-fs: INFO: recovery required on readonly filesystem.
EXT3-fs: write access will be enabled during recovery.
kjournald starting. Commit interval 5 seconds
EXT3-fs: xvda1: orphan cleanup on readonly fs
ext3_orphan_cleanup: deleting unreferenced inode 3932161
ext3_orphan_cleanup: deleting unreferenced inode 2762928
ext3_orphan_cleanup: deleting unreferenced inode 2763561


ext3_orphan_cleanup: deleting unreferenced inode 2756567
ext3_orphan_cleanup: deleting unreferenced inode 4162628
ext3_orphan_cleanup: deleting unreferenced inode 2767840
EXT3-fs: xvda1: 80 orphan inodes deleted
EXT3-fs: recovery complete.
EXT3-fs: mounted filesystem with ordered data mode.

I've been advised on another forum it's a hardware issue, but the Windows VMs never crash and I've never encountered a problem with them either.

Does anyone know what this is and what could be causing it? Additionally can anyone help determine the cause of the crashing? Thanks in advance.

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up vote 0 down vote accepted

There's not much to do here except a fsck.ext3 on your servers. When you say "a reboot fixes the problem" do you mean a reboot of the xenhost or of the linux guest ?

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Sorry, I meant a reboot of the Linux guests. When one of the Linux guests crash, both CPU 0 and 7 shoot up to 100% usage. I've noticed a small spike in HDD usage at the time the CPU shoots up. After that the server is non-responsive to SSH or console access and has to be forcefully rebooted via XenCenter. – Reado Oct 20 '10 at 16:00
the dmesg maybe just shows that the server recovered from the last hard reboot and successfuly restored the filesystem. You should start your machine with "xen create -c myguest" so you have a console opened all the time. Turn the screensaver off and watch the messages returned at the time of the crash. – Rosco Oct 21 '10 at 6:53

You can also start XenServer in serial console mode, if you have access to a serial port. When the XS reboots, one of the first things you'll see is a boot: prompt. type in "xe-serial" and hit enter. that will boot you into serial mode. you can then connect to the console, enable logging in putty or whichever program you are using, and then you'll get the messages you're looking for.

In terms of why the Windows VMs don't crash - are they all on the same storage? Same switches? Anything different about the path to the storage that the Linux VMs take vs the Windows ones?

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