I got similar problems (shutdown hanging, mount:/ is busy) with Ubuntu 14.04 on a Dell Precision WorkStation 390, after boot ing dmesg displayed a kernel 'Oops: 0000 [#1] SMP', a few lines below the 'i82975x_edac' is listed:
[ 7.951808] Oops: 0000 [#1] SMP [ 7.951943] Modules linked in: i82975x_edac(+) snd edac_core serio_raw soundcore mac_hid hid_generic usbhid hid ahci firewire_ohci libahci firewire_core crc_itu_t floppy tg3 ptp pps_core [ 7.952012] CPU: 0 PID: 309 Comm: systemd-udevd Not tainted 3.13.0-36-generic #63-Ubuntu [ 7.952012] Hardware name: Dell Inc. Precision WorkStation 390 /0DN075, BIOS 2.6.0 05/19/2008 [ 7.952012] task: ffff88007b988000 ti: ffff8800796e8000 task.ti: ffff8800796e8000 [ 7.952012] RIP: 0010:[<ffffffffa00c97ee>] [<ffffffffa00c97ee>] edac_create_sysfs_mci_device+0x23e/0x550 [edac_core] I blacklisted the i82975x_edac module and voila, the machine shuts down without problems. See also my bug: https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/1372006 -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1263704 Title: pci_devices does not terminate at computer shutdown To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/pm-utils/+bug/1263704/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
