DRAG DROP
You manage an Azure virtual machine (VM) named AppVM. The application hosted on AppVM
continuously writes small files to disk. Recently the usage of applications on AppVM has increased greatly.
You need to improve disk performance on AppVM.
Which Microsoft Azure Power Shell cmdlet should you use with each Power Shell command line? To
answer, drag the appropriate Microsoft Azure Power Shell cmdlet to the correct location in the PowerShell code. Each Power Shell cmdlet may be used once, more than once, or not at all. You may need to
drag the split bar between panes or scroll to view content.
Answer: 
Explanation:
Example:
This command gets the “MyVM” virtual machine running on the “myservice” cloud service, and then sets
the data disk at LUN 2 of the virtual machine to use ReadOnly host caching.
Windows PowerShell
C:\\PS>Get-AzureVM “myservice” -name “MyVM” | Set-AzureDataDisk -LUN 2 -HostCaching ReadOnly |
Update-AzureVMSet-AzureDataDisk
http://msdn.microsoft.com/en-us/library/dn495144.aspx
-HostCaching
Sets the host level caching settings of the disk. Possible values are: None, ReadOnly and ReadWrite (WriteOnly is NOT an option).
I think the correct answer is
Get-AzureVM “AppService” -name “AppVM” | SetAzureDataDisk -LUN 3 -HostCaching None | Update-AzureVM
From this url : https://docs.microsoft.com/en-us/azure/storage/storage-premium-storage
Should be None for write heavy data
Cache: VMs of the size series that support Premium Storage have a unique caching capability with which you can get high levels of throughput and latency, which exceeds underlying premium storage disk performance. You can configure the disk caching policy on the premium storage disks as ReadOnly, ReadWrite or None. The default disk caching policy is ReadOnly for all premium data disks and ReadWrite for operating system disks. Use the right configuration setting to achieve optimal performance for your application. For example, for read-heavy or read-only data disks, such as SQL Server data files, set the disk caching policy to “ReadOnly”. For write-heavy or write-only data disks, such as SQL Server log files, set the disk caching policy to “None”.
I agree +1