Perl quick and dirty to get blockdevices. Used only in zabbix low level discovery. Its ugly, and works for me and... oh, wait, its perl. :D

zabbix.blockdevices.discovery.pl

#!/usr/bin/perl
$first = 1;
print "{\n";
print "\t\"data\":[\n\n";
#Need fix here. Proc Partitions to rescue
for (`/usr/bin/iostat -d 1 1 | grep -v Device  | grep -v Linux| awk '{print \$1}' | sed '/^\$/d' `)
{
    chomp $_ ;
    print "\t,\n" if not $first;
    $first = 0;
    print "\t{\n";
    print "\t\t\"{#BLOCKDEVICES}\":\"$_\"\n";
    print "\t}\n";
}
print "\n\t]\n";
print "}\n";

zabbix.disks.tps.sh

#!/bin/bash
STATS=$(/usr/bin/iostat -d 1 1 $1 | grep -v Device  | grep -v Linux  | awk '{print $2}' | sed 's/,/./g') 

if [ -z $STATS ] ; then 
	echo "NOT SUPPORTED" 
else
	echo $STATS
fi

zabbix_agentd.conf

##User Parameter for disks 
UserParameter=disks.tps[*],/usr/local/bin/zabbix.disks.tps $1
UserParameter=disks.tps.discovery,/usr/local/bin/zabbix.blockdevices.discovery.pl