You can break out the record fields by processing the record string as a list of lines:

use strict;
use warnings;
use Data::Dumper;

my %records;
local $/ = "\n\n";

while (<DATA>) {
    next if !/^(\d+):(.*)/s;

    my ($id, $tail) = ($1, $2);
    local $/ = "\n";
    open my $recIn, '<', \$tail;

    while (<$recIn>) {
        chomp;

        #next if !/(\w+)\s*=\s*(.*)/;
        #
        #$records{$id}{$1} = $2;

        next if !/^\s*?([^=]+)\s*=\s*(.*)/;

        my ($key, $value) = ($1, $2);
        
        s/^\s+|\s+$//g for $key, $value;
        $records{$id}{$key} = $value;
    }
}

print Dumper(\%records);

__DATA__
...
[download]

Using the previous data prints:

$VAR1 = {
          '1' => {
                   'Capacity' => '288196762624 (268.4G)',
                   'WWN' => '06:00:00:00:05:00:00:00:00:00:00:00:00:00
+:00:03',
                   'Pool' => 'performance',
                   'Model' => 'STE30065 CLAR300',
                   'Maximum speed' => '6 Gbps',
                   'Health details' => '"The component is operating no
+rmally.  No action is required."',
                   'Vendor capacity' => '322122547200 (300.0G)',
                   'Part number' => '005049273',
                   'Enclosure' => 'DPE_0',
                   'Health state' => 'OK (5)',
                   'Serial number' => '6SJ2C6MV',
                   'Slot' => '0',
                   'Type' => 'SAS',
                   'User capacity' => '236420176896 (220.2G)',
                   'ID' => 'disk_dpe_0_0',
                   'Manufacturer' => 'SEAGATE',
                   'Name' => 'DPE Disk 0',
                   'Current speed' => '6 Gbps',
                   'Rotational speed' => '15000 rpm',
                   'Firmware revision' => 'ES0E'
                 },
          '2' => {
                   'WWN' => '06:00:00:00:05:00:00:00:01:00:00:00:01:00
+:00:03',
                   'Pool' => 'performance',
                   'Capacity' => '288196762624 (268.4G)',
                   'Slot' => '1',
                   'Serial number' => '6SJ28QF3',
                   'Health state' => 'OK (5)',
                   'Part number' => '005049273',
                   'Enclosure' => 'DPE_0',
                   'Model' => 'STE30065 CLAR300',
                   'Maximum speed' => '6 Gbps',
                   'Health details' => '"The component is operating no
+rmally.  No action is required."',
                   'Vendor capacity' => '322122547200 (300.0G)',
                   'ID' => 'disk_dpe_0_1',
                   'User capacity' => '236420176896 (220.2G)',
                   'Manufacturer' => 'SEAGATE',
                   'Type' => 'SAS',
                   'Rotational speed' => '15000 rpm',
                   'Firmware revision' => 'ES0E',
                   'Current speed' => '6 Gbps',
                   'Name' => 'DPE Disk 1'
                 }
        };
[download]

Note that local overrides the variable's value just for the current block so changing $/ inside the main loop doesn't affect while (<DATA>). open my $recIn, '<', \$tail; treats $tail as a file.

Update: Replaced commented out code to fix the single word matches for keys issue caught by tybalt89.