Synology - Cheatsheet Repairs Fdisk results in GPT mismatch GPT PMBR size mismatch (225279 != 250879) will be corrected by w(rite). To fix the above, run the following set of commands. 1. SSH into the server and log into root. sudo su 2. Run parted . parted 3. List all disks. print all 4. When it finishes listing the disks, it will ask you if you want to "Fix" the errors or not. Type fix . 5. Reboot the Synology device.