Comment 24 for bug 1164497

arbuntu, as per your https://launchpadlibrarian.net/161783564/BootDmesg.txt :
[ 9.468539] WARNING: at /build/buildd/linux-lts-quantal-3.5.0/drivers/iommu/intel-iommu.c:3294 quirk_ioat_snb_local_iommu+0xab/0xc0()
[ 9.468544] Hardware name: SUN FIRE X2250
[ 9.468545] BIOS assigned incorrect VT-d unit for Intel(R) QuickData Technology device

As well, as per http://www.oracle.com/technetwork/systems/patches/firmware/release-history-jsp-138416.html#X2250 an update is available for your BIOS (3A20). If you update to this during your maintenance window following https://help.ubuntu.com/community/BiosUpdate , does it change anything? If it doesn't, could you please both specify what happened, and just provide the output of the following terminal command:
sudo dmidecode -s bios-version && sudo dmidecode -s bios-release-date

For more on BIOS updates and linux, please see https://help.ubuntu.com/community/ReportingBugs#Bug_reporting_etiquette .

Thank you for your understanding.