How to Extend Partition using Diskpart?

October 15, 2018

You can extend a partition in Windows 10/8/7 with Diskpart command line or AOMEI Partition Assistant.

Why extend partition?

Sometimes, Windows users may find that their partition on the basic disk or the volume on the dynamic disk isn’t enough to store the data. Thus, a way to extend partition/volume may give a big help for users.

Windows operating system provides Disk Management which has the function Extend Volume that you can use to extend the size of your partition with an adjacent unallocated space. But if you want to use a command line to extend volume, you can use Windows command tool Diskpart.

Extend partition with Diskpart

Diskpart, as the disk management tool of Windows, can help you manage your disks in a good state. You can use it to extend an existing volume/partition by following the next steps.

Step1. Open the command-line window by clicking Start, typing: cmd, or you can press “WIN+R” and type “cmd”. In the command prompt, type:diskpart, press Enter.

Then, it will run Diskpart session.

Step2. At the Diskpart prompt, type: list disk.

Then, all disks will be list at the prompt.

Step3.Then, type:select disk n

n means disk number. Here, you choose the disk which has the partition you want to extend.

Step4. Type: list partition

The partition(s) on the selected disk will be listed.

Step5.Then, you can select the partition which you want to extend. Type: select partition n

n is the partition number you want to extend. Please make sure there is unallocated space behind the partition you want to extend.

Step6. Type: extend size=n

n is the size in MB you want to add the partition.

Then, it will remind you that Diskpart successfully extended the volume. Here is a screen shot of the details.

diskpart extend partitions

When you’re finished, type exit to end up this progress.

If you are extending volumes on dynamic disk, you can use “volume” to replace “partition”. However, Diskpart can only extend volumes created on dynamic disks, not the volumes created on the basic disk that you have upgraded. If you want to extend a volume on basic disks,  you will receive the error”Diskpart failed to extend the volume. Please make sure the volume is valid for extending.” To extend a basic volume, it must be raw or formatted with NTFS file system.

The command-line for Extending partition of partassist.exe

AOMEI Partition Assistant Professional is with Partassist.exe utility . It can resize(extend/shrink) partition without data loss from command prompt. Install AOMEI Partition Assistant Professional and open it by typing "cd + installation directory of AOMEI Partition Assistant Professional". For example: how to extend partition with Partassist.exe?

First, type:cd C:\Program Files\AOMEI Partition Assistant Professional Edition on 7.2, then, press Enter to open the program.

Next, you should type:partassist.exe /list

Then, it will list the basic situation of all your disk. Then, you can use the command to extend partition as you want. Like the following screen shot, type: /hd:2 /resize:H /extend:10GB /align, pressEnter, it will be executed.

PA Extend Partitions

Using AOMEI command line to extend partition, you can follow the other parameters below:

1.partassist.exe /hd:0 /resize:0 /extend:auto /align

or

partassist.exe /resize:F /extend:auto /align

Those two parameters can automatically extend a specified partition using the unallocated space on its both sides and align partition to optimize reading/writing speed.

2.partassist.exe /hd:0 /resize:0 /extend:right

or

partassist.exe /resize:F /extend:right

Those two parameters can automatically extend a specified partition using the unallocated space on its right side.

3.partassist.exe /hd:0 /resize:0 /extend:left /align

or

partassist.exe /resize:F /extend:left /align

Both of them can automatically extend a specified partition using the unallocated space on its left side and align the partition to optimize reading/writing speed.

4.partassist.exe /hd:0 /resize:0 /extend:1000

or

partassist.exe /hd:0 /resize:0 /extend:10GB

Both of them can Extend a specified partition using 1000MB or 10GB unallocated space on its right side.

Notes:

> "/hd" followed by disk number, which starts with 0.

> "/resize" followed by partition number or drive letter, and the partition number starts with 0. If the specified value is drive letter, disk number can be ignored.

> The value of "/extend" can be left, right, auto or specified size.

> "/align" means align a partition to optimize reading/writing speed. If the beginning of a partition is changed when resizing it (in other words, move the beginning of a partition to a new location, forward or backward), then the "/align" works. But if the beginning of a partition is not changed when resizing it, then the "/align" doesn’t works.

> By default, the specified size is in MB, and GB is also available.

The partassist.exe can help you solve the problem that the Diskpart cannot do. You can use it to manage your disk more flexible.

The easiest way to extend partition with AOMEI Partition Assistant

Not everyone can use CMD well. Diskpart extend partition is more suitable for people who know it deeply. It cannot be any wrong while operating. Once there is a wrong step, it may cause a big damage. Fortunately, the AOMEI Partition Assistant also provides you extend partition with GUI (graphical user interface). It only need a few clicks.

Step1.Launch AOMEI Partition Assistant Professional. It will display its main interface. To extend partition, here you can do with resize partition, merge partitions, move partition.

1> If there is unallocated partition adjacent to the partition you want to extend, you can right click the partition, select Resize Partition to extend the partition with the unallocated space.

Resize Partition

Then, drag the bar towards the right to extend partition with the unallocated space.

Resize

2> If the unallocated space is not adjacent to the partition you want to extend, you can right click the partition near to the unallocated space, select Move Partition to move the unallocated space to the partition you want to extend. Then, use the Resize Partition to extend partition.

Move Partition

Then, drag the partition to the left, and it will be moved.

Move

3> The most effective way is using Merge Partitions to extend partition. No matter there is unallocated space or not, you can right click the partition you want to extend, select Merge Partitions.    

Merge Partition

Then, you can select the unallocated space or other existing partition to extend the partition you want to extend.

Merge

Notes:Each operation need to click Apply at the tool bar would be executed.

Diskpart extend volume will fail if there is no unallocated space near to the partition you want to extend. But AOMEI Partition Assistant GUI can extend partition for Windows 7/8/10 under those situations. It can help you manage your hard drive alone, even you know a little about computer.