This article describes how to correlate between the SCSI IDs exposed by VMware (visible within the Administrative UI) and the virtual disks visible on your Windows virtual server. (virtual, VM, RDP, Windows, storage)
- This article assumes that the additional storage has been added to the server as described in How to Add Additional Local Storage (Disk) to a Cloud Server
- RDP Access is required to the Windows server and the article assumes an open RDP connection
Content / Solution:
On Windows Server VMs, it can be difficult - unless you are already familiar with the Disk Management interface - to find the SCSI ID value associated with each additional drive. This article shows exactly where to find the SCSI ID for each disk that will map to the value shown in the Administrative UI for the disk.
After adding local storage to the server (How to Add Additional Local Storage (Disk) to a Cloud Server) the administrative UI displays each disk within it's SCSI Controller, with SCSI ID, Disk Size, and Disk Speed:Note: SCSI ID 0 is the default Disk. 2 additional disks have been added to the Server (SCSI ID 1 and SCSI ID 2).
Important Note: SCSI ID 7 is reserved and will be skipped within bot Windows and VMware, i.e. in Windows on the virtual server, Disk 7 in the Disk management view will have a Target ID (SCSI ID) of 8. Disk 8 will have a Target ID of 9 and so on.
Follow the steps below to see how these disks are displayed on the Windows Virtual Server:
Within an open RDP session to your Windows server, open the Device Manager and expand the "Disk drives" node. This window shows all the virtual disk devices attached to your VM and indicates with an icon difference whether the disk is enabled and disabled. Both disks shown below are enabled. Note that this step is not essential but is useful in demonstrating that the same properties dialog is pointed to by the Device Manager and Disk Management functions:
Right click a disk in this view and select properties
The VMware Virtual disk SCSI Disk Device Properties are displayed. Note the Target ID; this maps to the SCSI ID in VMware. It will always be "0" for the boot (OS Storage) disk.
Now open the Server Manager and expand the "Storage" node, then select Disk Management. This view shows only the enabled disk devices from the Device Manager view. The numbering displayed, "Disk 0", "Disk 1" and so on does not indicate the underlying SCSI ID in all cases.
To access the actual SCSI ID for a disk, right click the heading of any disk row as shown below:
Windows will display the same dialog shown earlier when selecting properties for a disk in the Device Manager view. However accessing it here allows you to correlate between notional volumes in Windows (with or without assigned drive letters) and the SCSI IDs of their underlying disks.
Target Id 1 in the window below identifies this as the same disk selected in the Device Manager view looked at earlier:
Note: If you plan on removing any previously added local storage, you can perform a safety check by first identifying the drive letter of the disk you wish to remove and then disabling the drive within Windows to ensure that the correct disk is being targeted.
This is an optional procedure that can provide reassurance before removing a disk.
In the example below we are using a disk with a 5GB partition in place, with the drive letter "E:".
First, use the steps above to determine the disk to disable.
Then right click on the disk in the Device Manager view:
Note: it is not possible to disable the boot or OS Storage volume:
However, disks that have been added as additional local storage (How to Add Additional Local Storage (Disk) to a Cloud Server) can be disabled:
Windows will ask you to confirm that you wish to disable the disk:
Click Yes to disable the disk. The disk will no longer be visible in the Disk management section under the Storage node of Server Manager:
However the disk will remain in the Device Manager, with a different icon to highlight its disabled status:
Right click and select enable if you wish to re-enable the disk:
Note this process does not destroy the volume on the disk, it appears as before: