You could loop through and fill in the missing holes: 
use warnings;
use strict;
use Data::Dumper;
$Data::Dumper::Sortkeys=1;

my %list;
while (<DATA>) {
    my ($k, $v) = split;
    $list{$k}{$v}++;
}

for my $k (keys %list) {
    for my $stat (qw(active passive failed other)) {
        $list{$k}{$stat} = 0 unless exists $list{$k}{$stat};
    }
}

print Dumper(\%list);


=for output

$VAR1 = {
          'lun1' => {
                      'active' => 2,
                      'failed' => 1,
                      'other' => 0,
                      'passive' => 0
                    },
          'lun2' => {
                      'active' => 0,
                      'failed' => 0,
                      'other' => 0,
                      'passive' => 1
                    },
          'lun3' => {
                      'active' => 0,
                      'failed' => 0,
                      'other' => 1,
                      'passive' => 0
                    }
        };

=cut


__DATA__
lun1 active
lun2 passive
lun1 failed
lun3 other
lun1 active

[download]

In reply to Re: is a hash of hashes the right thing by toolic
in thread is a hash of hashes the right thing by bhu731

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