The base operating system version for TrueNAS 11.0-U2 is FreeBSD 11-STABLE, bringing in a number of bug fixes, performance improvements, and new drivers. FreeBSD ports have been updated to follow the FreeBSD 2016Q4 branch.

TrueNAS 11.0-U2 includes the following fixes from FreeNAS:

11.0-RC: https://bugs.freenas.org/projects/freenas/issues?query_id=378

11.0-RC2: https://bugs.freenas.org/projects/freenas/issues?query_id=379

11.0-RC3: https://bugs.freenas.org/projects/freenas/issues?query_id=411

11.0-RC4: https://bugs.freenas.org/projects/freenas/issues?query_id=393

11.0: https://bugs.freenas.org/projects/freenas/issues?query_id=325

11.0-U1: https://bugs.freenas.org/projects/freenas/issues?query_id=404

11.0-U2: https://bugs.freenas.org/projects/freenas/issues?query_id=418 

11.0-U2.1: https://bugs.freenas.org/projects/truenas/issues?query_id=426

11.0-U2.2: https://bugs.freenas.org/projects/truenas/issues?query_id=427

In addition, these fixes are specific to TrueNAS:

Add iSCSI ALUA support
Temporary communications loss with AD server no longer disables AD
Create VMFS Datasets using vCenter
Add checkbox to enable iSCSI ALUA
iSCSI ALUA portal datagrid changes
Fix hactl traceback
Add additional IPMI info to freenas-debug
Add Interlink and CriticalGroupN to network debug and ifconfig output
Add option to shutdown standby node
Reorder System tab
Add serial mode option to ISO installs
Keep host and NetBIOS names consistent in HA pair
Allow VHID of 10 or 20
Destroy a mirrored swap when partitioning the disks
Add option to reboot standby node on sync to peer
Remove hactl section from Guide as GUI should be used instead
Integrate vCenter 2.1.0 Plugin
Make use of X10 LEDs
Remove repetitive HA update instructions  in TrueNAS User Guide
Clarify Proactive Support description in TrueNAS User Guide
Add missing  HA timeout parameter to API
Fix CARP traceback
Load freenas_sysctl module at boot
Propagate service start/stop on master node to standby
vCenter fixes for Python 3
Fix middleware database sync
Logs filled with useless pciconf/zpool calls
Fix Save Debug traceback
Dismissed Alerts still light warning LED
Cannot create a debug when 1 node is down
Fix migration issue when upgrading HA pair
Fix Cloud Sync
Improve wording of Proactive Support alert
Fix Wizard traceback
Add mlx5 modules to TrueNAS kernel
Fix "Upgrade Install" error
Update vCenter plugin to 2.1.0
Regenerate ALUA config when iSCSI is enabled
Fix traceback if gateway is empty
Update Samba to address CVE-2017-11103
FreeBSD Security Advisory FreeBSD-SA-17:05.heimdal for TrueNAS 11
Add warning to disable failover when configuring network address
Fix traceback when running alert.py directly
Log hasyncd errors on first instance