How to Use Diskpart Command Line to Extend Server Disk Partition?

December 23, 2014

Diskpart is a Windows self-contained utility to extend server disk partition by using scripts, remote session or directly typing commands. Besides, some kinds of third party of software can do it much better.

Brief introduction of diskpart

Diskpart is a command line which deals with disks, partitions or volumes by taking advantage of scripts, remote session or directly inputting orders. Diskpart is exactly the potential utility which augments the Disk Administrator graphical user interface and enables a superset of the actions which are supported by the Disk Management snap-in. Before you can use diskpart commands on a disk, partition, or volume, you must firstly list and then select the object to give it focus. When an object has focus, any Diskpart commands that you type can act on that object.

How to extend server disk partition with diskpart

Please follow the steps bellow to extend partition in server using diakpart:

  • Step1. Click start and type "diskpart" in the column, then press Enter on the keyboard.
  • Step2. Type "list volume" and press Enter on the keyboard to display the existing volumes on the computer.
  • Step3. Type "select volume Y" and press Enter on the keyboard to focus on volume Y; Y is the number or drive letter of the partition that you want to extend.
  • Step4. Type "extend [size=n] [disk=n] [noerr]" to extend volume Y to disk n of size n.


  • Contents in the square brackets are unnecessary. That is to say, you can only type "extend" to extend the size of the selected volume.
  • "size=n " specifies the space, in megabytes (MB), to add to the current partition. If you do not specify a size, the disk is extended to use all the next contiguous unallocated space.
  • "disk=n " determines the dynamic disk on which to extend the volume. Space equal to n is allocated on the disk. If no disk is specified, the volume is extended on the current disk.
  • "noerr" is for scripting only. When an error is thrown, this parameter specifies that Diskpart continue to process commands as if the error did not occur. Without the noerr parameter, an error causes Diskpart to exit with an error code.
  • If there is no unallocated space behind partition Y, you cannot extend it. In order to extend it, you must make some unallocated space and put it behind volume Y.

Now, Partition Y has been extended with the unallocated space successfully.

Several kinds of third party software to extend server disk partition

Though diskpart is Windows server self-contained function and is free of charge, it has many disadvantages. The most unacceptable one is that for most users, it is difficult to use. Therefore, to make it easy for users to manage their server disk volumes, many kinds of software come into being, such as AOMEI Partition Assistant Server works fast and keeps your data safe. It has a great popularity among users all around the world with its supporting Windows Server 2003, 2008, 2012 R2.

Here are steps of extending server disk partition with Partition Assistant.

Step1. Download, install and start Partition Assistant Server. In the main console, right-click the target partition that you are going to extend and choose “Resize Partition”.

Step2.In the next window, drag the graphic bar of the partition rightwards to enlarge the target partition. You can also set the size in bellow to execute exact enlargement. If you put some space on the left of target partition by writing a number in “Unallocated space before”, you are really moving the target partition!

Note:There must be some unallocated space on the hard disk to extend a partition on it. If there isn’t, you have to create some before you do.


Step3. Click “OK” to have a preview of the extended partition. If there is nothing incorrect, click “Apply” to confirm the change.

Except for partition extension, Partition Assistant still provide a lot of other functions to its numerous users, such common services as “Create/Delete Partition”, very useful functions as “Disk Copy Wizard” and new service as “Windows To Go Creator”. Except server edition support server system, there is a lite edition which also can be used in server and what is more? It is free of charge! However, lite edition has fewer functions than server edition. Therefore, to choose a server edition or lite one, it all depends on your needs.