Comment 2 for bug 1404322

For some reason your filesystem is being corrupted. Can you boot the installer and choose the memtest option from the menu? Let it run for at least 15 minutes and see if it finds any errors. Also you don't currently have any important data on that drive correct? If so, please run sudo badblocks -b 4096 -c 1024 -w -s /dev/sdb. This will test the drive and can take some time. It will also wipe out whatever data is on the drive, so again, only run it if there is nothing important on that drive.