Bisected. Bug seen after commit 045065d8a300a37218c548e9aa7becd581c6a0e8 [SCSI] fix qemu boot hang problem.
Actually, the problem is not with that commit that is perfectly fine. That commit merely lets the real bug be triggered. Real bug is with scsi host lock and likely to be triggered by mixing a slow and a fast device on the same IDE/SATA channel. Bug is also biting other distros. See https://bbs.archlinux.org/viewtopic.php?id=189324 Bug is known to kernel developers. https://lkml.org/lkml/2015/8/16/44 https://bugzilla.kernel.org/show_bug.cgi?id=87581 Bug is fixed by following patch by Christoph Hellwig, that unfortunately is not yet applied upstream https://lkml.org/lkml/2014/11/20/581 ** Bug watch added: Linux Kernel Bug Tracker #87581 http://bugzilla.kernel.org/show_bug.cgi?id=87581 ** Changed in: linux (Ubuntu) Status: Incomplete => Confirmed -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1451277 Title: Extremely high IOWait and processes hungs after utopic->vivid upgrade with Iomega Zip drive (IDE) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1451277/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
