Management of an instance's disk space
In the meantime, as a workaround, you could create a new instance with a standard quota and copy the content over.
Increase disk capacity
If you would like to have more space for your instance, you can increase the size of the attached hard disk.
Increasing the size of your disk is done by purchasing addition disk quota, which will then be automatically added to the size of your instance disk. Therefore, the process must be carried out from within the instance whose size you are trying to increase, and not from another instance!
On the instance management screen, in the Information section, click “Change” next to “Disk space”.
The following Modification screen allows you to change both the total disk space and the size of the instance.
The disk space displayed in the interface represents your total available space, including the 20 GB the instance comes with.
The maximum size of a disk linked to an instance is 1 TB (1000 GB).
Just click Submit, then complete the payment process. The operation to add disk quota will complete automatically within a few moments.