My Saucy dom0 is also affected by this. I wasn't able to get the dmesg in text but I attached a picture of it.
The problem seems to be this: ata1.00: qc timeout (cmd 0xec) ata1.00: failed to IDENTIFY (I/O error, err_mask=0x4) Then the SATA link back down a on speed (6 -> 3 Gbps) and the same occurs over and over. The same kernel boots just fine when outside of Xen. System info: $ lsb_release -rd Description: Ubuntu 13.10 Release: 13.10 $ apt-cache policy linux-image-`uname -r` xen-hypervisor-4.3-amd64 linux-image-3.11.0-13-generic: Installed: 3.11.0-13.20 Candidate: 3.11.0-13.20 Version table: *** 3.11.0-13.20 0 500 http://archive.ubuntu.com/ubuntu/ saucy-updates/main amd64 Packages 500 http://security.ubuntu.com/ubuntu/ saucy-security/main amd64 Packages 100 /var/lib/dpkg/status xen-hypervisor-4.3-amd64: Installed: 4.3.0-1ubuntu1 Candidate: 4.3.0-1ubuntu1 Version table: *** 4.3.0-1ubuntu1 0 500 http://archive.ubuntu.com/ubuntu/ saucy/universe amd64 Packages 100 /var/lib/dpkg/status ** Attachment added: "Xen dom0 ATA error" https://bugs.launchpad.net/ubuntu/+source/xen/+bug/1127214/+attachment/3903962/+files/DSC_1024.jpg -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1127214 Title: Xen Kernel cannot boot due to ATA erros/timeouts To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xen/+bug/1127214/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs