Here is my approach, not using complex regular expressions. Stuff all colon-separated lines into a hash. When a new start-of-record is encountered, print out what you want from the hash, then clear the hash. This operates line-by-line, and only one record is in memory at a time.

use strict;
use warnings;

my %data;
while (<DATA>) {
    if (/Symmetrix ID:/) {  # start of new record
        print_record(%data) if %data;
        %data = ();
    }
    elsif (/:/) {
        chomp;
        my ($k, $v) = split /\s*:\s*/;
        $k =~ s/^\s+//;
        $data{$k} = $v;
    }
}
print_record(%data) if %data;

sub print_record {
    my (%data) = @_;
    my @params = (
        'Device Serial ID',
        'Vendor ID',
    );
    for (@params) {
        print "$_: $data{$_}\n";
    }
    print "\n";
}

__DATA__
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Prints for 2 records:

Device Serial ID: 6000062081
Vendor ID: EMC

Device Serial ID: 6000062082
Vendor ID: EMC2
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