I posted the headaches I've been through this weekend at the tail end of another thread:viewtopic.php?f=16&t=3055
I realized that since that thread is solved, chances are, few if any will read my tacked-on-the-end posts. So I'll start a new thread.
Basically, I nuked my MEPIS 8.5 system when I foolishly decided to try upgrading from Lenny repos to Testing repos. Not a problem for those with knowledge, perhaps; but I tend to wade into things that are over my head.
Anyway, couldn't boot after installing Testing. Hours of frustration trying to figure-out what happened. Re-installing MEPIS 8.5 worked, sort-of. Then I got stupid again, and tried updating to Stable. I figured the problem might have been updating two levels (Lenny to Wheezy). Well, one level was enough, and I was back to a non-bootable (to X, anyway) system.
Using a spare computer to search through forums, I noticed mention of problems with "libc6" updgrades, for various distros. Each time I tried upgrading through apt-get, I encountered messages telling me I needed to manually stop xdm or kdm (might not have those spelled right) and a bunch of other stuff; in connection with libc and/or glibc.
This may or may not be the only problem. Rokytnji identified a problem in the thread linked-to above, which had to do with separate root and home partitions; which I tend to use. See the thread linked-to above for details. It gets solved by using UUID (whatever that is) labels for drives, rather than /dev/sda1-type labelling - both in Grub and /etc/fstab.
Anyway, I can now boot into X; after modifying menu.lst and /ect/fstab with the UUID stuff. But I'm still scared to do a full apt-get dist-upgrade! I have done so probably half-a-dozen times this weekend, and each time I end up with either total inability to boot (if I installed Grub to root) or command-line-only (if I installed Grub to the MBR or whatever it's called).
I don't really understand all the various posts about libc6; but I'm pretty sure it's involved.
Any and all thoughts on this pesky dilemma are most welcome!