Hi,
I have realized, or think I figured it out ;), that Rockstor is not doing any TRIM on mounted SSDs. Nor by using discard as a mount optione (perhaps not the best option anyhow) or using the fstrim.timer option (or a cron job) to trim unused data from SSDs and keep them live longer.
Can this be implemented, for me, I am running rockstor on a small SSD which makes the system just horrible fast 
and applications like plex which huge databases more than usable 
Enable TRIM would be a great idea on one or the other way.
Some documentation I found, but there is for sure more out there anyhow
http://blog.neutrino.es/2013/howto-properly-activate-trim-for-your-ssd-on-linux-fstrim-lvm-and-dmcrypt/
https://devhen.org/enable-trim-support-for-ssds-on-linux/
https://wiki.archlinux.org/index.php/Solid_State_Drives
https://wiki.archlinux.org/index.php/Btrfs#SSD_TRIM
I resolved it in the meantime using a weekly cronjob and a script found at on of the articles mentioned above
create file and open in nano
nano /etc/cron.weekly/fstrim
copy and paste the script
#!/bin/sh
LOG=/var/log/fstrim.log
echo [ $(date) ] $(/sbin/fstrim -v / 2>&1) >> $LOG
echo [ $(date) ] $(/sbin/fstrim -v /home 2>&1) >> $LOG
set the executable flag
chmod +x /etc/cron.weekly/fstrim
do a testrun
/etc/cron.weekly/fstrim
open the log file
cat /var/log/fstrim.log
[ Mon Sep 14 13:17:49 CEST 2015 ] /: 67.8 GiB (72746291200 bytes) trimmed
[ Mon Sep 14 13:19:10 CEST 2015 ] /home: 67.8 GiB (72749588480 bytes) trimmed