Can I increase/decrease RAM?

Under certain conditions, this is possible by modifying the current VPS plan. Go to the server detail in the user interface on the "Configuration" tab. You will see a list of all compatible VPS plans. Next, select a change method:

CPU & RAM only: This will only increase or decrease the vCPU and RAM of your VPS, not disk size. This can be reversed. This option is therefore best suited for RAM change.
Disk, CPU & RAM: This will increase the disk size, CPU and RAM of your VPS. This is a permanent change and cannot be reversed. After upgrading, the partition size must be adjusted via the disk management client (except for WebApps servers, where it will happen automatically).

Changing VPS parameters may result in migration. At the end of the migration, VPS will restart. VPS may not be available during migration. Migration time depends on disk size and type. You can follow the progress on the "Overview" tab in the VPS detail. The change retains the original VPS properties (data, assigned IP addresses, etc.).