REVIEW: http://review.gluster.org/14719 (cluster/tier: fix detach tier error message) posted (#1) for review on release-3.8 by Dan Lambright (firstname.lastname@example.org)
All 3.8.x bugs are now reported against version 3.8 (without .x). For more information, see http://www.gluster.org/pipermail/gluster-devel/2016-September/050859.html
This bug is getting closed because the 3.8 version is marked End-Of-Life. There will be no further updates to this version. Please open a new bug against a version that still receives bugfixes if you are still facing this issue in a more current release.