I'd create a state machine to parse the file. The state ($section in the below code) tells me what the parser expects to find. I also need to store the current zone and cluster to be able to attach the new information to the correct part of the structure. 
#!/usr/bin/perl
use warnings;
use strict;

my %zone;

my $section = 0;
my ($current_zone, $current_cluster);

while (<>) {
    if (! $section) {
        if (/^Zone ID/) {
            $section = 'zones';

        } elsif (/^Cluster ID/) {
            $section = 'clusters';

        } elsif (/^Host Name/) {
            $section = 'hosts';

        } elsif (my ($name) = /^(\S+)$/) {
            if (exists $zone{$name}) {
                $current_zone = $name;

            } elsif (exists $zone{$current_zone}{cluster}{$name}) {
                $current_cluster = $name;
            }
        }

    } elsif ('zones' eq $section) {
        if (my ($id, $name) = /(\S+)\s+(\S+)/) {
            $zone{$name}{id} = $id;

        } elsif (/^$/) {
            $section = 0;
        }

    } elsif ('clusters' eq $section) {
        if (my ($id, $name, $type, $mem, $cpu)
            = /^(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)$/
        ) {
            $zone{$current_zone}{cluster}{$name} = { id   => $id,
                                                     type => $type,
                                                     mem  => $mem,
                                                     cpu  => $cpu };
        } elsif (/^$/) {
            $section = 0;
        }

    } elsif ('hosts' eq $section) {
        if (my ($host, $vms, $status, $state)
            = /^(\S+)\s+(\S+)\s+(\S+)\s+(\S+)$/
        ) {
            $zone{$current_zone}{cluster}{$current_cluster}{host}{$hos
+t}
                = { vms    => $vms,
                    status => $status,
                    state  => $state };

        } elsif (/^$/) {
            $section = 0;
        }
    }

}

use Data::Dumper; print Dumper \%zone;

[download]
($q=q:Sq=~/;[c](.)(.)/;chr(-||-|5+lengthSq)`"S|oS2"`map{chr |+ord
}map{substrSq`S_+|`|}3E|-|`7**2-3:)=~y+S|`+$1,++print+eval$q,q,a,

[download]

In reply to Re: Generate Hash of hashes by reading a large Input file by choroba
in thread Generate Hash of hashes by reading a large Input file by pr33

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