1finalStr = ''
2Object.keys(obj).forEach(function(key) {
3  if (obj[key].name === 'mountpoints') { // only get sizes for mountpoints
4    var value = obj[key].value;
5    Object.keys(value).forEach(function(name) { // add all sizes to string
6      finalStr += '"' + name + '" - ' + value[name].size + ';';
7    }); //update
8  }
9}); //update
10
11if (finalStr.length > 0) { // at least one entry was added
12  finalStr.slice(0, -1);
13}