Tonight I decided I wanted to tweak the configuration of my Debian install on my netbook (Ideapad S10-2) to work better with the SSD I put in it.
I have done this before and never had any issues but just in case I double-checked what I was doing against the Debian SSD Optimization guide and everything seemed right.
At this point I rebooted and things went wrong. The system refused to mount the volume as anything but read-only complaining about the "discard" flag not being recognized.
I've tried booting from several different live CDs (well, over PXE anyway) but they all refuse to mount the volume for one reason or another (after running through modprobe dm-mod; cryptsetup luksOpen et al) and I suspect it's the wrong way to go.
Well, the problem I'd rather solve is to figure out a way to make the crippled system (which boots with the root partition mounted read-only) mount the root partition rw by somehow ignoring the
/etc/crypttab so that I can change those back, reboot and have things back the way they were.
Edit: It just dawned on me why it didn't work, the filesystem for the root partition is
ext3 for some reason. I had naively assumed it would be
ext4. So the solution is clearly to somehow mount while ignoring the discard flag.