3.12-sles12.series 3.12.74-60.64.40 (SLES12 SP1)
4.4-sles12.series 4.4.103-92.56 (SLES12 SP2)
4.4-sles12sp3.series 4.4.103-6.38 (SLES12 SP3)
+4.4-ubuntu14+16.series 4.4.0-85.108 (Ubuntu 14.04.5 LTS)
+4.4-ubuntu14+16.series 4.4.0-85.108 (Ubuntu 16.04)
See lustre/ChangeLog for supported client kernel versions.