I followed this to align and enable trim on my SSD:
https://forum.pfsense.org/index.php?topic=86139.0
Step-by-step I did the following:
*** This erases everything from the disk***
1.) Boot into partedmagic and dd zeros or secure erase the target ssd
2.) Boot the pfSense liveCD in default mode
3.) Drop to shell instead of running the installer
4.) #gpart destroy -F ada0s1 (only needed if you did not secure erase first)
5.) #gpart destroy -F ada0 (only needed if you did not secure erase first)
6.) #gpart create -s mbr ada0
7.) #gpart add -t freebsd -b 504 ada0
8.) Leave the shell and start the install process
9.) Custom Install
10.) Skip Format Disk
11.) Skip Partition
12.) Install Boot Block
13.) Format Disk
14.) I had to manually change the "/" partition to a size smaller than the disk or I would get an error. I ended up making an 80GB partition and 16GB swap on my 120GB intel 320SSD.
15.) CTRL-C at reboot and enable trim
16.) #/sbin/tunefs -t enable /dev/ada0s1a
Reboot
Execute Shell command in the web interface to run
gpart show
Start of slice plus start of partition should be divisible by 8.
For my disk it worked out to be:
(504+16)/8 = 65 Aligned
(504+167772160)/8 = 20971583 Aligned
This worked for me after a lot of trial and error. If you choose the wrong thing during install it will nuke the manual partition and you will end up not aligned and have to start the process all over.
Unless I am missing something this will get you aligned slices and trim enabled on your SSD.
