Updated as per markus request for viewing disk space

Added two methods to Diskprovider:-
getFixedDrives, getTotalSize
and letting UI decide on how to display space.
and changed from vent to listenTo
(cherry picked from commit 5aa00cfb6498d4731d5d880c346afe747a61024e)

src/NzbDrone.Api/DiskSpace/DiskSpaceModule.cs

@@ -3,26 +3,30 @@ using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
+using NzbDrone.Common;
 
 namespace NzbDrone.Api.DiskSpace
 {
     public class DiskSpaceModule :NzbDroneRestModule<DiskSpaceResource>
     {
-        public DiskSpaceModule():base("diskspace")
+        private readonly IDiskProvider _diskProvider;
+
+        public DiskSpaceModule(IDiskProvider diskProvider):base("diskspace")
         {
+            _diskProvider = diskProvider;
             GetResourceAll = GetFreeSpace;
         }
+
         public List<DiskSpaceResource> GetFreeSpace()
         {
-            return (DriveInfo.GetDrives()
-                .Where(driveInfo => driveInfo.DriveType == DriveType.Fixed)
+            return (_diskProvider.GetFixedDrives()
                 .Select(
-                    driveInfo =>
+                    x =>
                         new DiskSpaceResource()
                         {
-                            DriveLetter = driveInfo.Name,
-                            FreeSpace = SizeSuffix(driveInfo.TotalFreeSpace),
-                            TotalSpace = SizeSuffix(driveInfo.TotalSize)
+                            DriveLetter = x,
+                            FreeSpace = _diskProvider.GetAvailableSpace(x).Value,
+                            TotalSpace = _diskProvider.GetTotalSize(x).Value
                         })).ToList();
         }
 

src/NzbDrone.Api/DiskSpace/DiskSpaceResource.cs

@@ -9,7 +9,7 @@ namespace NzbDrone.Api.DiskSpace
     public class DiskSpaceResource : RestResource
     {
         public string DriveLetter { get; set; }
-        public string FreeSpace { get; set; }
-        public string TotalSpace { get; set; }
+        public Int64 FreeSpace { get; set; }
+        public Int64 TotalSpace { get; set; }
     }
 }

src/NzbDrone.Common/DiskProvider.cs

@@ -42,6 +42,8 @@ namespace NzbDrone.Common
         void SetFolderWriteTime(string path, DateTime time);
         FileAttributes GetFileAttributes(string path);
         void EmptyFolder(string path);
+        string[] GetFixedDrives();
+        long? GetTotalSize(string path);
     }
 
     public class DiskProvider : IDiskProvider
@@ -475,5 +477,15 @@ namespace NzbDrone.Common
                 DeleteFolder(directory, true);
             }
         }
+
+        public string[] GetFixedDrives()
+        {
+            return (DriveInfo.GetDrives().Where(x => x.DriveType == DriveType.Fixed).Select(x => x.Name)).ToArray();
+        }
+
+        public long? GetTotalSize(string path)
+        {
+            return (DriveInfo.GetDrives().Single(x => x.Name == path)).TotalSize;
+        }
     }
 }

src/UI/System/DiskSpace/DiskSpaceLayout.js

@@ -4,8 +4,9 @@ define([
     'marionette',
         'backgrid',
         'System/DiskSpace/DiskSpaceCollection',
-        'Shared/LoadingView'
-], function (vent,Marionette,Backgrid,DiskSpaceCollection,LoadingView) {
+        'Shared/LoadingView',
+        'Cells/FileSizeCell'
+], function (vent,Marionette,Backgrid,DiskSpaceCollection,LoadingView,FileSizeCell) {
     return Marionette.Layout.extend({
         template: 'System/DiskSpace/DiskSpaceTemplate',
 
@@ -17,35 +18,32 @@ define([
                 {
                     name: 'driveLetter',
                     label: 'Drive',
-                    cell: Backgrid.StringCell
+                    cell: 'string'
                 },
                 {
                     name: 'freeSpace',
                     label: 'Free Space',
-                    cell: Backgrid.StringCell
+                    cell: FileSizeCell,
+                    sortable:true
                 },
                 {
                     name: 'totalSpace',
                     label: 'Total Space',
-                    cell: Backgrid.StringCell
+                    cell: FileSizeCell,
+                    sortable:true
                 }
             ],
 
         initialize: function () {
             this.collection = new DiskSpaceCollection();
-            this.collectionPromise = this.collection.fetch();
-
-            vent.on(vent.Events.CommandComplete, this._commandComplete, this);
+            this.listenTo(this.collection, 'sync', this._showTable);
         },
         onRender : function() {
             this.grid.show(new LoadingView());
         },
         
         onShow: function() {
-            var self = this;
-            this.collectionPromise.done(function() {
-                self._showTable();
-            });
+            this.collection.fetch();
         },
         _showTable: function() {
             this.grid.show(new Backgrid.Grid({