I was requested to make a dump of our main database and load it onto one of our test boxes yesterday. The reload attempt began around midmorning. However when I left, around nine hours later, it had not yet finished the run. Additionally, when viewing the results of a ps ax command, the time (which I am assuming is the time it has actually run) at a few minutes before I left was listed as 29:something, which leads me to believe that, over the course of nine hours of run, the database load process only actually received 29-30 minutes of processor time.

What might be causing that? Given that the database load was, to my knoweldge, the only thing running on the server in question other than background processes, what are the likeliest suspects, and how do I modify them so as to prevent something like this from happening in the future?

What distro? What DB (inc ver)?
Have you checked what other progs are running? Are you sure they're not causing the problem.

A common problem that causes slow reloads is not disabling indexes. For every rec inserted, it re-calcs the index list...
for a fast reload:
1. disable all indexes
2. load data
3. enable indexes.
you also get a 'better' index layout.