#!/bin/bash
HDDs=`cat /proc/diskstats | awk '/[sh][d][a-z] / {print$3}'`
FIRST="1"
JSON="{ \"data\":["
for HDD in ${HDDs}; do
    if [ $FIRST == "0" ]; then
        JSON="${JSON},"
    fi
    JSON=${JSON}"{ \"{#HDD}\":\"${HDD}\"}"
    FIRST="0"
done
JSON=${JSON}"]}"
echo ${JSON}