I looked back into the mailing list archives and there has been a thread titled: "blkfront problem in pvops kernel when barriers enabled". As far as I understand, this is a problem of the backend driver (which is part of the host code), offering the barrier method for syncing but then failing with empty requests. In my testing with Ubuntu based dom0 (which is Xen 4.1.2) guest will be using cache flush for syncs. And I did not experience any of the observed problems.
So this looks to me like it needs to be fixed in the host (Xenserver or Debian) by making sure to have the following change: # HG changeset patch From: Jan Beulich <jbeul...@novell.com> # Date 1306409621 -3600 # Node ID 876a5aaac0264cf38cae6581e5714b93ec380aaa # Parent aedb712c05cf065e943e15d0f38597c2e80f7982 Subject: xen/blkback: don't fail empty barrier requests -- 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
