Ubuntu is slowly getting unusable

The default Document Viewer in Ubuntu 14.04 is Evince. Recently it started to have problems with many PDF files that are opened by other PDF viewers (Okular, Acroread) without problems. Actually Evince opens them, but the window remains invisible. I tried to change the PDF viewer, but Ubuntu has apparently removed all means to do so in version 14.04 short of going into the command line and editing configuration files by hand: what a progress!

Mounting individual partitions from disk dumps

You can make disk dumps from individual partitions or from a hard drive that contains more than one partition. The ladder has the advantage that you can restore the computer by dumping back the image onto the same or another hard drive. But if you want to access an individual partition from a hard drive image, you need to know where the partition boundaries are. You can note them down from the output of fdisk. However, fdisk -l gives the partition boundaries, but the unit is sectors. You need to multiply this number by the logical sector size to get the partition boundaries in bytes.