Update from 11.04 to 12.04 crashed -- now what?

Hold shift at boot and choose recovery mode, then select root and run:

sudo fuser -vki /var/lib/dpkg/lock;sudo dpkg --configure -a; reboot

Should be ok

Upon restart, I held shift key... was a momentary purple background on screen, then screen went black. No option to choose recovery mode ever appeared. Screen remains black. The Hard Disk light is flashing however, it's doing something, now 10 minutes after the restart... I will leave it alone for a bit and see what happens.

The Hard Drive activity has completed... the screen is now dark, however the mouse is active and shows a hollow X cursor....

Did you upgrade to 11.10 first, then upgrade to 12.04?

No

The prompt to update to 12.04 appeared on my system. I simply clicked the link. No warning was given that the update could not be accomplished.

I have now rebooted. The system is repeating it's original behavior of continuous disk activity behind a black and unresponsive screen.

I made an 12.04 install disk and loaded it. I was able to read the files on the root drive, which is a solid state drive. I was able to read info on the external MyBook drive. I was NOT able to read the files on the 2 hard drives, there appears to be a permission error... additionally, a mirrored array across the two hard drives was defined in the original version of Ubuntu and that is not even recognized, although the data appears to still hold the disk space.

If I go back and substitute a new solid state drive and re-install the 11.04, can I recover those hard drive partitions? What is the process for recovering them and the permissions necessary to access them?

A correction to my earlier observations - I was incorrect. The original version WAS 11.10

I have installed another solid state drive and returned the system to it's previous release state, we'll stay on 11.10 for awhile as the 12.04 update process is now deemed unreliable.

Could have tried a clean install of Precise instead. I always reinstall for new releases as I've seen too many issues with upgrades.

As soon as I finish recovering the original material I need off the original SSD, I will probably do just that. My only concern about reinstalling for a new release is that if there are upgrade problems, sometimes that indicates that the release could probably benefit from further 'delta' testing in it's release state where there are enough users to really shake it out...

Thanks for your help. Much appreciated.

I suggest you get a backup, what if the drive fails (SSDs only have a limited life), where is your data then?

Originally, the intention was to have the SSD be a system-only disk... like a Live CD... with no live data per se to preserve on it. I configured the backup utility to backup the stuff related to the apps that was written in the File System folders to an external drive, adding things to the backup list I saw were being added...

After this failure, I have a new system SSD and I took the old one and plugged it in as another 'data' drive and have recovered the important stuff off it... all in all, a much simpler process than Windows ever would have been... ironically, the hardest job was figuring out how to get the dual-monitor system working properly.

Again, thanks for your help.