I am trying to find if the ZFS filesystem has added support for Trim to Raid 5? I am setting up an SSD array in Raid 5. I also would like to know if there is any good software raid 5 alternatives to an LSI raid controller card? Keep in mind, I am using ZFS on Ubuntu.
TRIM and DISCARD support for ZFS is currently in alpha. Pawel Dawidek wrote the initial code for FreeBSD and Etienne Deschamps ported it to Linux.
For ZoL, you need to compile the experimental code yourself and set the zfs_notrim=0 option.
This feature will be disabled by default for a long while on most ZFS systems, but it exists and it works.