Hello everyone,

A few blog times ago, I showed you step by step how to create bidirectional mirrored storageand replacing a defective disk and repairing storage space.

In today’s blog post, I’ll go through how to expand and change the storage space and size of an existing two-way mirror.

First, we need to check the current state of the current virtual disk before making any changes.

Open PowerShell and retrieve the current virtual disk information:

As you can see, we have mirror storage with a 363GB SSD level and a 2.2TB hard drive level, but we no longer have room to expand the existing volume.


Current volume “D.“The disk space is 2.53 TB and the free size is 1 TB.

In my presentation, adding 1 TB to the HDD tray, as a side note, the same is true if you also resize the SSD tray.

Now, before we start increasing the capacity of the pool and resizing the virtual disk, you need to pay special attention to how many physical disks can you add to your existing storage space?

The answer to this question depends what options were chosen when the virtual disk was originally created.

Consider the following example:

You have a storage pool with a 2-column two-way mirror space. A two-column, two-way mirror space suggests that you expand the capacity of the pool for four sets of mirror spaces, meaning you have to multiply the number of columns by the number of copies, and since we have 2 columns, you need at least four physical disks.

Another thing to remember is that once the plates have been added to the pool, there is no balancing mechanism. So existing disks are filled first before data is written to the added disks. Therefore, the number of columns must be carefully selected when creating a virtual disk, because you cannot change the number of columns when a virtual disk is created.

With Get-VirtualDisk you will find many things in the virtual disk storage area you created.


Since I use bidirectional mirror space with one column, I add a 2 X 1 TB hard drive to my JBOD.


Next, the newly added disks are added to the existing Storage Pool and then the media type is set to HDD.



Let’s now look at the maximum capacity we can add to storage and expand the existing amount.


As you can see, we can add roughly 1.1 TB.

Here’s one more important thing to keep in mind: When editing storage, you need to specify a new total size and not a magnified amount, so in my example above, the current HDD level is 2232GB, I need to add 1116GB (new) + 2232GB ) = 3348 GB total hard drive, this of course if I have to increase the total capacity otherwise. The same principle applies if you resize the SSD tray.

Continue and increase full capacity.



Last but not least, we need to expand the existing section that expands the volume. “D.“And finally, confirm the changes.




Microsoft is fine Storage overview which goes into more detail and is worth reading.

Hopefully the notes and screenshots above will illustrate how you can expand and resize your storage space as needed.

Next time … Enjoy your day!
/ Charbel


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