After upgrading our various Extreme VMs (Control and Analytics) to version 8.0.2, Veeam backups were failing because they couldn't create a VMware snapshot. Some googling found that it's an issue relating to the Ubuntu upgrade from 12.04 to 14.04 that leaves a reference to '/var/lib/ureadahead/debugfs/tracing' in '/etc/mtab' after rebooting. Another reboot fixes the problem, or you can just edit '/etc/mtab' and remove the line with ureadahead in it.
