* Only do lvm/md if the corresponding file/command exist.
  + Much like I do with DO_ZFS checks etc...
* THe SAS2LP port can be one or two chars, to fix the find.
* Check for hdparm before running it. Just in case.
* Tripple check to find disk by id.
  + Split it's multiline command line.
* Fix regexp when checking ZFS - if (when) DID or tmpnam was
  empty, the regexp ended up to be '|sda|' which matches every
  line!
  + Catch removed disk(s).