Limit Disk I/O In Proxmox

Two VMs with 1 IPv4 for each one.

A. 240GB disk, using 10GB LOL.
B. 300GB disk, using 60GB.

I’d like to take backups, move them to a temporary server and start the VMs to check they work as expected (not sure if I need around 540GB or 70GB), then reinstall my Proxmox server and restore de backups.

If the problem is the hardware I won’t be able to put everything back, so I will probably need to stay in the temporary server some days until I get a new dedi.