use Parallel::ForkManager ();
my $pm = Parallel::ForkManager->new(3);
foreach my $fw (qw(fw1 fw2 fw3 fw4 fw5)) {
   $pm->start and next; 
   exec "remotelogfile $fw logfile > /var/$fw.log";
   die("Unable to launch \"remotelogfile $fw\": $!\n");
}