This turned out to be a XenServer bug related to the interaction between blkback and barriers; my contact at Citrix has produced a dom0 kernel patch which fixes the issue. I'm told the fix will be incorporated in the next point release of XenServer.
** Changed in: linux (Ubuntu) Status: Triaged => Invalid ** Changed in: linux Status: Confirmed => Invalid -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/824089 Title: Xen blkfront i/o errors prevent boot in domU To manage notifications about this bug go to: https://bugs.launchpad.net/linux/+bug/824089/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs