Find the New Drives connected through iSCSI

I am writing a powerscript that connects to a target through ISCSi. I need to find the new drive letters (F:, G:, …) that is created after connecting. Is there any direct way to find that? MY script would be

New-IscsiTargetPortal -TargetPortalAddress $VirtualDeviceIp
Connect-IscsiTarget -NodeAddress $VirtualDeviceIQN
#Get the drives newly attached

Though not straight I tried another way of doing it.

$initial=Get-Volume
New-IscsiTargetPortal -TargetPortalAddress $VirtualDeviceIp
Connect-IscsiTarget -NodeAddress $VirtualDeviceIQN
$final=Get-Volume
#Now compare $initial and $final to find the newly attached disks

But I dont know implement the second idea too :(

Solution

Compare the DriveLetter property of the two sets:

Compare-Object $initial $final -Property 'DriveLetter'

Expanding the property will give you just the drive letter:

$driveLetter = Compare-Object $initial $final -Property 'DriveLetter' |
               select -Expand 'DriveLetter'

To be on the safe side you could add a filter that restricts results to "right side" items (i.e. newly added drives), thus excluding "left side" items (i.e. removed drives):

$driveLetter = Compare-Object $initial $final -Property 'DriveLetter' |
               ? { $_.SideIndicator -eq '=>' } |
               select -Expand 'DriveLetter'