Why expand the OS-disk?
In a Virtual Machine (VM), the OS-disk is where the Operating System (OS; for instance Windows or Linux) is installed but also encompasses your general desktop and other folders (basically anything on the C:-drive). It is always recommended to store your data on the Z:-disk, as this is the fileshare that everyone in the workspace can access. Moreover, data on the Z-disk is snapshotted (backup of all the changes compared to the previous day) every evening, whereas data on the OS-disk is not being snapshotted.
However, you might have noticed that fileshares (in this case the Z:-disk) can be very slow. Unpacking .zip files is way faster if you transfer it to your desktop (= part of the C-disk). Another example is loading heavy images such as CT scans into software. This is way faster when done from your desktop. The C-disk size is 127 GB (on Windows; 16 GB on Linux) by default and there has to be enough space for the OS. In some cases it is therefore desired to increase the size of the OS-disk or to gain access to an extra data disk.
After selecting the disk size, check the Confirm Up-Size box and Up-Size to save the changes.
Read below on how to configure the disk to use the expanded volume!

As a self-service, you can expand data disks up to 2TB.
If a disk is 4 TiB or less, you should deallocate your VM and detach the disk before expanding it beyond 4 TiB. If a disk is already greater than 4 TiB, you can expand it without deallocating the VM and detaching the disk.
How to request (OS-)disk expansion more than 2Tb?
- Contact your Research Support member via a ticket. Choose your organization and request for a change. Please let us know:
- As with anything that incurs costs: permission of the accountable (this will be checked).
- The workspace name.
- On which VM you want to have the disk expanded and the OS (Windows/Linux).
- The Research Support member will contact you with advice on either increasing the OS-disk or putting an extra disk in place.
For Research Support Member
- Detach a data disk for resizing above 2TB