I am running 12.04 LTS, and almost every time I shut down my system, my root fails to mount on the next bootup, usually after an update.
In this particular case, I can see my filesystem when running on live CD, but every time I boot, I see the following sequence of messages cycle in an endless loop (process IDs removed):
ata1.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
ata1.00: BMDMA stat 0x24
ata1.00: failed command: READ DMA
ata1.00: cmd c8/00:08:b0:f7:46/00:00:00:00:00/e0 res 51/40:08:b0:f7:46/40:02:02:00:00/e0 Emask 0x9 (media error)
ata1.00: status:{DRDY ERR}
ata1.00:error:{UNC}
end_request: I/O error, dev sda, sector 4650928I boot off of a relatively new 60GB solid state disk drive, and in the past when I have run into this issue, I use fsck to detect and fix errors. But fsck runs clean on my partition, so i am uncertain how to approach the problem.
13 Answers
There was an Input Output error at your Hard Disk sda part, at sector 4650928. You can boot from Ubuntu Live cd/dvd/usb, start Disks Utility, try to see the SMART data and test your sda disk.
4The DMA read error was real. There was indeed a bad sector and replacing the SATA cables did not help. I finally tried to re-install from LiveCD, and the installation failed due to my bad disk drive. I originally went with an SSD because I wanted fast bootup, and was told that the Corsair Nova 2 was a good one, although more recent reviews (and this experience) refute that.
So the answer to this question should be marked as being due to a failed solid state drive.
I encountered a similar problem today. I unpluged sata cable and reconnected my hard drive to motherboard and it worked !
