you are actually using an old kernel: 126.96.36.199, unless you have specific reason to run this kernel, usually there aren't, update to the most recent kernel, 188.8.131.52-pclos3.
to use mylivecd with that kernel you need to specificy the option --lzma
, because the default compression actually used from mylivecd is not supported from that old kernel.
About partitions and umount: you don't need to execute mylivecd from a terminal console, you only need to log out from the current user and then log in as root
, still using the graphics interface.
open a console, and from there copy & paste the following commands:
verify what partitions remain mounted, (all partitions somewhat in use will and must remain mounted), using the command:
the max size you backup using mylivecd is around 10/11 Gb, not more.
I noticed you have a separate /tmp, please note that some area in /tmp is actually used when running mylivecd.
Also, if you are using a separate /boot, take care to not unmount that partition, or remount it, because it's vital for
a bootable liveCD iso.