doc: Clarify documentation of reweight command.

This caused some discussions on the mailing list, so let's try to be clear
about the meaning of an OSD weight.

Signed-Off-By: Andre Noll <maan@systemlinux.org>

diff --git a/doc/control.rst b/doc/control.rst
index 2c69ddc112c00fc7904affc5ec3a9e79175accd6..133e0ac1a5e4ffcffa7e0aa1fec5dc80b3e5c0e0 100644 (file)
--- a/doc/control.rst
+++ b/doc/control.rst
@@ -152,7 +152,9 @@ resending pending requests. ::
 
        $ ceph osd reweight N W
 
-Sets the weight of osdN to W. ::
+Set the weight of osdN to W. Two OSDs with the same weight will receive
+roughly the same number of I/O requests and store approximately the
+same amount of data. ::
 
        $ ceph osd reweight-by-utilization [threshold]