/// <summary>
/// Tries to resize the VHD file, using the parameters specified.
/// </summary>
/// <param name="newSizeInGb">The new size of the VHD file, in gigabytes.</param>
/// <param name="blobUri">The <see cref="Uri"/> to locate the VHD in the Azure Storage account.</param>
/// <param name="accountName">The name of the Azure Storage account.</param>
/// <param name="accountKey">The key of the Azure Storage account.</param>
/// <returns>Returns <see cref="ResizeResult.Error"/> if there were issues while trying to do the resize operation.
/// Returns <see cref="ResizeResult.Shrink"/> if this is a shrink operation which needs user confirmation.
/// Returns <see cref="ResizeResult.Success"/> if everything went fine.</returns>
public ResizeResult ResizeVhdBlob(int newSizeInGb, Uri blobUri, string accountName, string accountKey)
{
NewSize = ByteSize.FromGigaBytes(newSizeInGb);
// Check if blob exists
blob = new CloudPageBlob(blobUri);
if (!string.IsNullOrEmpty(accountName) && !string.IsNullOrEmpty(accountKey))
{
blob = new CloudPageBlob(blobUri, new StorageCredentials(accountName, accountKey));
}
try
{
if (!blob.Exists())
{
Console.WriteLine("The specified blob does not exist.");
return(ResizeResult.Error);
}
}
catch (StorageException ex)
{
Console.WriteLine("The specified storage account credentials are invalid. " + ex.ToString());
return(ResizeResult.Error);
}
// Determine blob attributes
Console.WriteLine("[{0}] Determining blob size...", DateTime.Now.ToShortTimeString());
blob.FetchAttributes();
originalLength = blob.Properties.Length;
// Read current footer
Console.WriteLine("[{0}] Reading VHD file format footer...", DateTime.Now.ToShortTimeString());
footer = new byte[512];
using (var stream = new MemoryStream())
{
blob.DownloadRangeToStream(stream, originalLength - 512, 512);
stream.Position = 0;
stream.Read(footer, 0, 512);
stream.Close();
}
footerInstance = Footer.FromBytes(footer, 0);
// Make sure this is a "fixed" disk
if (footerInstance.DiskType != FileType.Fixed)
{
Console.WriteLine("The specified VHD blob is not a fixed-size disk. WindowsAzureDiskResizer can only resize fixed-size VHD files.");
return(ResizeResult.Error);
}
if (footerInstance.CurrentSize >= (long)NewSize.Bytes)
{
// The specified VHD blob is larger than the specified new size. Shrinking disks is a potentially dangerous operation
// Ask the user for confirmation
return(ResizeResult.Shrink);
}
return(DoResizeVhdBlob());
}
private static int ResizeVhdBlob(long newSize, Uri blobUri, string accountName, string accountKey)
{
bool isExpand = true;
// Check if blob exists
var blob = new CloudPageBlob(blobUri);
if (!string.IsNullOrEmpty(accountName) && !string.IsNullOrEmpty(accountKey))
{
blob = new CloudPageBlob(blobUri, new StorageCredentials(accountName, accountKey));
}
try
{
if (!blob.Exists())
{
Console.WriteLine("The specified blob does not exist.");
return(-1);
}
}
catch (StorageException ex)
{
Console.WriteLine("The specified storage account credentials are invalid.");
return(-1);
}
// Determine blob attributes
Console.WriteLine("[{0}] Determining blob size...", DateTime.Now.ToShortTimeString());
blob.FetchAttributes();
var originalLength = blob.Properties.Length;
// Read current footer
Console.WriteLine("[{0}] Reading VHD file format footer...", DateTime.Now.ToShortTimeString());
var footer = new byte[512];
using (Stream stream = new MemoryStream())
{
blob.DownloadRangeToStream(stream, originalLength - 512, 512);
stream.Position = 0;
stream.Read(footer, 0, 512);
stream.Close();
}
var footerInstance = Footer.FromBytes(footer, 0);
// Make sure this is a "fixed" disk
if (footerInstance.DiskType != FileType.Fixed)
{
Console.WriteLine("The specified VHD blob is not a fixed-size disk. WindowsAzureDiskResizer can only resize fixed-size VHD files.");
return(-1);
}
if (footerInstance.CurrentSize >= newSize)
{
Console.WriteLine("The specified VHD blob is larger than the specified new size. Shrinking disks is a potentially dangerous operation.");
Console.WriteLine("Do you want to continue with shrinking the disk? (y/n)");
while (true)
{
var consoleKey = Console.ReadKey().KeyChar;
if (consoleKey == 'n')
{
Console.WriteLine("Aborted.");
return(-1);
}
if (consoleKey == 'y')
{
isExpand = false;
break;
}
}
}
Console.WriteLine("[{0}] VHD file format fixed, current size {1} bytes.", DateTime.Now.ToShortTimeString(), footerInstance.CurrentSize);
// Expand the blob
Console.WriteLine("[{0}] Resizing containing blob...", DateTime.Now.ToShortTimeString());
blob.Resize(newSize + 512);
// Change footer size values
Console.WriteLine("[{0}] Updating VHD file format footer...", DateTime.Now.ToShortTimeString());
footerInstance.CurrentSize = newSize;
footerInstance.OriginalSize = newSize;
footerInstance.Geometry = Geometry.FromCapacity(newSize);
footerInstance.UpdateChecksum();
footer = new byte[512];
footerInstance.ToBytes(footer, 0);
Console.WriteLine("[{0}] New VHD file size {1} bytes, checksum {2}.", DateTime.Now.ToShortTimeString(), footerInstance.CurrentSize, footerInstance.Checksum);
// Write new footer
Console.WriteLine("[{0}] Writing VHD file format footer...", DateTime.Now.ToShortTimeString());
using (Stream stream = new MemoryStream(footer))
{
blob.WritePages(stream, newSize);
}
// Write 0 values where the footer used to be
if (isExpand)
{
Console.WriteLine("[{0}] Overwriting the old VHD file footer with zeroes...", DateTime.Now.ToShortTimeString());
blob.ClearPages(originalLength - 512, 512);
}
// Done!
Console.WriteLine("[{0}] Done!", DateTime.Now.ToShortTimeString());
return(0);
}
