doc/rados: update OSD_BACKFILLFULL description

Document that this warning can happen even when the OSDs' limits
haven't hit the backfill_full_ratio.

Signed-off-by: Ponnuvel Palaniyappan <pponnuvel@gmail.com>
(cherry picked from commit 198a9e02cb934802fcb5d5d06b05e3662a4b5cab)

diff --git a/doc/rados/operations/health-checks.rst b/doc/rados/operations/health-checks.rst
index a8fa8243fbce0b5e50b9f1ca6d70f5be7591a745..d63fbb2226e3f72fc2bdfd012243b7ffb24d901f 100644 (file)
--- a/doc/rados/operations/health-checks.rst
+++ b/doc/rados/operations/health-checks.rst
@@ -355,10 +355,10 @@ existing data should be deleted in order to free up space.
 OSD_BACKFILLFULL
 ________________
 
-One or more OSDs has exceeded the `backfillfull` threshold, which will
-prevent data from being allowed to rebalance to this device.  This is
-an early warning that rebalancing may not be able to complete and that
-the cluster is approaching full.
+One or more OSDs has exceeded the `backfillfull` threshold or *would* exceed
+when the currently mapped backfills finish, which will prevent data from being
+allowed to rebalance to this device.  This is an early warning that rebalancing
+may not be able to complete and that the cluster is approaching full.
 
 Utilization by pool can be checked with: