Comment 3 for bug 1094397

There seem to be some errors communicating with your drives:

Dec 28 18:07:59 ubuntu kernel: [ 121.244045] ata1: softreset failed (device not ready)
Dec 28 18:07:59 ubuntu kernel: [ 121.244057] ata1: limiting SATA link speed to 1.5 Gbps
Dec 28 18:07:59 ubuntu kernel: [ 121.244060] ata1: hard resetting link
Dec 28 18:08:00 ubuntu ubiquity[3862]: log-output -t ubiquity laptop-detect
Dec 28 18:08:04 ubuntu kernel: [ 126.444067] ata1: softreset failed (device not ready)
Dec 28 18:08:04 ubuntu kernel: [ 126.444077] ata1: reset failed, giving up
Dec 28 18:08:04 ubuntu kernel: [ 126.444094] ata1: exception Emask 0x40 SAct 0x0 SErr 0x800 action 0x7 t4
Dec 28 18:08:04 ubuntu kernel: [ 126.444097] ata1: SError: { HostInt }
Dec 28 18:08:04 ubuntu kernel: [ 126.444104] ata1: hard resetting link

I'd try resetting cables and see if that resolves the issue.