Comment 3 for bug 2049685

There are a lot of disk IO errors in the log:

[ 12.972221] ata2.00: exception Emask 0x0 SAct 0x1010 SErr 0x40000 action 0x0
[ 12.972228] ata2.00: irq_stat 0x40000008
[ 12.972230] ata2: SError: { CommWake }
[ 12.972233] ata2.00: failed command: READ FPDMA QUEUED
[ 12.972235] ata2.00: cmd 60/18:20:08:1f:68/00:00:08:00:00/40 tag 4 ncq dma 12288 in
                        res 41/40:00:0c:1f:68/00:00:08:00:00/00 Emask 0x409 (media error) <F>
[ 12.972240] ata2.00: status: { DRDY ERR }
[ 12.972242] ata2.00: error: { UNC }

Your disk might be dying.