concat keys json
finalStr = ''
Object.keys(obj).forEach(function(key) {
if (obj[key].name === 'mountpoints') { // only get sizes for mountpoints
var value = obj[key].value;
Object.keys(value).forEach(function(name) { // add all sizes to string
finalStr += '"' + name + '" - ' + value[name].size + ';';
}); //update
}
}); //update
if (finalStr.length > 0) { // at least one entry was added
finalStr.slice(0, -1);
}