Azure Files preview - access shared folder in IIS and FileZilla - azure

Question

I'm interested in load balancing 2+ Windows VMs in Azure. My primary requirement, though, is that an 'uploads' folder would need to be consistent between each VM. Files in this folder are FTPed by our admin users, and they would then need to select these files in a C# MVC Web app. As you may connect through FTP to one VM, but a Web connection might be to another, the uploads have to be centralised.
It looked as if the new Azure Files, currently in Preview, would help, in that they let me set up a shared drive that each of the VMs could access. My thought was that FileZilla Server would allow FTPing up to this shared 'drive', and the Web app would access it to show the contents.
I've signed up to the Azure Files Preview, and set up the share, persistently mapping it to Drive Z for the sake of experimentation. I've also created a new user and made sure they too have persistent mapping to this same drive as Z.
But I can't seem to do anything with this outside of the Remote Desktop. FileZilla, despite having its Service set to log on using this new account, won't show the contents of this drive, or write anything to it. Likewise my Web App isn't able to access the file contents, despite switching Passthrough Authentication to this new account for the virtual folder.
Does anyone know any way of accessing this drive either through the network path or drive letter? Is this just not possible with Azure Files as they are? Are there any other solutions to sharing some blobs across VMs, but treating it as a local drive or network share?
[UPDATE]
This might help. Having set up the share, and used cmdkey and net use while in a cmd prompt runas a specially created user (as suggested in http://blogs.msdn.com/b/windowsazurestorage/archive/2014/05/27/persisting-connections-to-microsoft-azure-files.aspx), if I point a virtual folder in IIS to this share, using the specific account created, and Test Connection, I get:
Test: Authentication (green tick; "The specified user credentials are valid")
Test: Authorization (red cross; "The path does not exist or environment variables in the path could not be expanded to verify whether it exists.")
While still in a runas cmd prompt, I can access the share, so it's not a specific permissions issue. It just seems to be that IIS cannot use that user to access the share, for some reason. The limitation of Azure Files is that I cannot specifically grant any kinds of permissions on the folder within that share.

Answer 1

What worked for me is the following:
Create a new account
Set the IIS App Pool Identity to a this specific user
Set the IIS App Pool Load User Profile property to true
start a cmd promt as this user (runas)
do cmdkey and net use (with /persistent:true switch), as you described
create IIS Virtual Diretory with physical path set to UNC share path (not the mapped drive)
A little PowerShell snippet for point 5:
$share = "your-storage-account.file.core.windows.net\yoursharename"
$usr = "your-storage-account"
$key = "your-storage-key"
#store credentials for the network share - must be done for the user that will run the app pool
cmdkey /add:subclub.file.core.windows.net\images /user:$usr /pass:$key
net use z: "\\$share" /user:$usr $key /persistent:yes

Answer 2

The answers here proved helpful.
Setup
Create a new user {appuser}
Open a command windows as the user
runas /user:{appuser} cmd.exe
In the new {appuser} cmd window use
cmdkey /add:{storage-account}.file.core.windows.net
/user:{storage-account} /pass:{account-key}
Set the IIS Application pool to use {appuser}
4b. Set LoadUserProfile to true
Notice no need for the net use. Don't need the mapped drive.
Code
Now here's the key piece. From your app you must write to the UNC path.
\{storage-account}.file.core.windows.net\
ex.
File.WriteAllText("\\\\{storage-account}.file.core.windows.net\\share\test.txt", "contents goes here");