Ive been running pfSense on a Soekris Net5501 for some time. It’s capable and stable but I have been running it from a compact flash card with limited space which eventually kept me from upgrading to the latest versions and from running the graphing back-end; so I’ve upgraded it to run on an SSD. There is a noticeable speed increase and now I have room for all the logging and graphing I would ever need.
After downloading the current pfSense ISO for a full install I booted the CD from the Thinkpad with the SSD attached via a USB > SATA adapter. After the CD booted I chose the “Install” option and chose the advanced option. Then in my case I chose the “embedded” option since the Soekris is headless and needs the serial/no vga kernel. I did no custom partitioning sine I intended to use the SSD only for pfSense. After the install completed, I put the SSD in the Soekris, attached the serial cable to the Thinkpad abd booted it up. At first boot the kernel will fail to find the root partition on the SSD which is not unusual since it was installed on a different machine. At the propmt you will only need to manually enter the proper drive/slice designation and then the boot will continue normally. Once fully running I had to ssh into the Soekris and edit the fstab with the proper drive/slice info for the “/” and “swap” partitions, reboot to confirm the changes.