FIX: Partitioning and Formatting Additional Test Volumes on SLC5 x64

Turns out, that SLC5 runs into disk space issues with the bigger test cases just as SLC6 used to do before. This adapts the partitioning, formatting, and mounting of additional disk space from the SLC6 context to the SLC5 one.
Unfortunately SLC5 comes with an older version of `parted` that lacks a machine readable output option. Hence, I needed to parse the human readable output which might be unstable. However, since we talk about SLC5, I consider updates to this parted version pretty unlikely.