About six months ago I installed Ubuntu 14.04 on my laptop with full disk encryption (FDE).
Now I am considering turning off FDE because I think the feature is making my system unstable. The risk of data theft seems less likely than the risk of system failure.
From the following, does it sound like FDE is likely at fault? Or should I be looking at the disk itself?
The disk is an Intel SSD. hdparm reports a model number "INTEL SSDSC2BW240A3".
To reduce disk writes I have put /tmp on tmpfs and removed set the noatime attribute for the rest of the disk. All other filesystem settings are the default, I believe.
At boot about a month ago the computer refused my decryption password. It acted as if it was the wrong password. Quite stressful!
I booted from the live CD and managed to decrypt the disk by giving the same password to the file manager prompt. The files were all still there, phew!
At the next boot from disk, the FDE system accepted the same password. Strange!
Now several times a week I encounter I/O errors make the system unusable and cause me to lose unsaved work.
Without warning, any and all of the following can happen:
Menu icons appear as white pages with red X marks.
LibreOffice will freeze when I try to save some changes to a document. It is stuck until force it to quit and lose the changes. Then it doesn't start again.
pgAdmin will display two errors every time I execute a query: "Can't write to log file" and "Can't write to history file".
If the query tries to read any data not already cached in memory by PostgreSQL, the server responds with a "read-only file system" error.
Firefox works for a bit, presumably because it's caching responses in memory. Without warning it will disappear.
Most basic of all, I can't even cleanly shutdown the system.
When I open a terminal and run shutdown, I see something like "/sbin/shutdown exec: I/O error"
I would supply more accurate repros, but it's quite hard to capture them when the system enters this state.
The only way out is to hold the power button until the system turns off hard.
When I turn it on again, the FDE system appears to do a quick consistency check after it accepts my password. I've been lucky so far.
I've taken a backup of all the important things.
I followed Fabby's instructions to test the disk using smartmontools.
Here is a link to the pre-test output: http://paste.ubuntu.com/9925956/
Here is a link to the post-test output: http://paste.ubuntu.com/9926195/