[Techtalk] Unknown computer error

[David Sumbler]

On Mon, 2015-04-27 at 20:52 +0100, David Sumbler wrote:
> My computer, running Ubuntu 12.04, suddenly froze this evening.  I
> opened a LibreOffice document, but it did not display quite quickly as
> it normally does.  Instead, the window that had opened remained empty
> but greyed out.
> 
> I expected it to clear within a few seconds, but it didn't.  So I tried
> closing some other programs that I had running, but they all turned grey
> and the windows refused to close.  Eventually everything seemed to
> freeze: I couldn't even get to a console using Ctrl-Alt-F1.  So I forced
> the computer to stop, and booted it again.
> 
> It seemed to boot up normally, but when I tried to start  a program
> (opening Chrome in Gnome) it froze again.
> 
> I did another forced stop (by holding the on-off button for several
> seconds) and booted another time.
> 
> This time the desktop seemed again to be unresponsive, but I was able to
> get to a console.
> 
> In the console I got the following messages repeatedly, every 3 seconds:
> 
> ata 3.00: status { DRDY ERR }
> ata 3.00: error { UNC }
> ata 3.00: exception Emask 0x0 SAct 0x0 SErr 0x0 action 0x0
> ata 3.00: BMDMA stat 0x65
> ata 3.00: failed commadn: READ DMA EXT
> ata 3.00: cmd 25/00:08:68:35:55/00:00:30:00:00/e0 tag 0 dma 4096 in
>           res 51/40:04:6c:35:55/40:00:30:00:00/00 Emask 0x9 (media
> error)
> 
> I had just finished copying all this (by hand), when the loop
> terminated.  I now found that simple commands in the console seemed to
> work normally, and then I was able to get back to Gnome, which now seems
> to be working normally.
> 
> Can somebody shed any light on the above?  Is my hard drive on the
> blink, or is it something else?
> 
> David

Further to the above:

After repeating the same process as before, and waiting several minutes
for the 3-second loop to stop, I found the following message on the
Gnome desktop:

GConf error: Configuration server couldn't be contacted: D-BUS error:
Did not receive a reply. Possible causes include: the remote application
did not send a reply, the message bus security policy blocked the reply,
the reply timeout expired, or the network connection was broken.

I seem to be able to open text documents, jpeg files, etc. without any
problem in Gnome.  But I have tried several LibreOffice files, and they
all refuse to open.  Each time this happens now I seem to be able to
force close the window after clicking on the close button.  This did not
work the first time I experienced this problem.

The files I am trying to open are all on my local hard drive.
Fortunately they are in my Dropbox folder, and I can access them from my
other machines.

David