Update on VHD Mount Behavior in Windows Azure VM with latest Windows Azure SDK 1.4 and updated Guest OS

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Some VHD Mount behavior seen in
Windows Azure VM:

-
A mounted VHD gets un-mount
after 30 minutes even when the process which mounted the VM exits

-
A mounted VHD will
still be mounted after the process which mounted the VM exits

 

Here is an explanation on above described behavior:

With Windows Azure Application (Web,
Worker and VM Role) based on Windows Azure SDK 1.3 and older:

When
you mount a Windows Azure Drive, a thread is created in your process to
maintain the temporary signature the drive uses to authenticate with Windows
Azure Storage. If your process exits,
this thread is destroyed and your drive will be unmounted in about 30 minutes
because the authentication stops working. This

This behavior will exist with all
Guest OS Version 1.x or 2.x.

 

With Windows Azure Application (Web,
Worker and VM Role) based on Windows Azure SDK 1.4 and later:

Beginning with Azure SDK version
1.4 (or later) and Guest OS versions 1.9 or 2.1 (or later), VHD mount will
persist even after the process that mounted the drive exits.

Note:

-
For web and worker roles, it is
necessary for the application to be using both the correct SDK and Guest OS.

-
For VM roles, the integration
components in SDK 1.4 are sufficient for the mounts to persist.

 

If you would like to access VHD
uploaded for the VM Role like normal page blobs, it is not possible in current
Windows Azure.

 

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