[SOLVED] Proxmox: Can i mirror the system-ssd to another ssd with boardtools?

Hi! Love my proxmox, so i spent him/her 2 new ssd's. 1x 2TB ssd (2,5") and 1x 4TB m.2-ssd (2280).

My server has 2 ssd-slots and one m.2-slot and there is now only one 2,5"-256GB-ssd inside.

My fault: I thought the system-ssd would be an 2,5"-sdd, so i can simply add the two new disks to the server, BUT now - after i opened the server - i saw it is an m.2-256GB-ssd. That means there are only two 2,5"-slots free.

What do you think?

Solution 1: I give back the m.2 and buy another 2,5"-ssd.

Solution 2: I mirror the systenmdisk to another 2,5"-300GB-ssd that i have lying around here and use the 2 new bought ssd's.

Question to solution 2: Is there a tool in proxmox that can mirror the system-disk and do i have to change a lot handish afterwards?

[EDIT / SOLUTION] You can clone the proxmox-system-disk to another with clonezilla. Rescuezilla did not work (issues with LVM's).
I did not had to edit anything. Booted and all services seem to work.

THANK YOU!