Looks fine for me!
The modules are core and your producing a maximal seed.
Still think it's exaggerated for your problem...
... but it's a good generic solution for similar tasks! =)
My only concern is readability, better use something like ord $char with an explicit loop var my $char
Anyway you are still operating on the assumption that hostnames are always different, since I don't know your project this might be ok or not.
Generating a random seed at installation time would prevent this "problem".
In reply to Re^6: How do I make a random shuffle deterministic?