doc/glossary: improve "BlueStore" entry

Initially s/backend/back end/ but then I added a little more information
about BlueStore's use of RocksDB to map object names to block locations
on disk.

Co-authored-by: Anthony D'Atri <anthony.datri@gmail.com>
Signed-off-by: Zac Dover <zac.dover@proton.me>
(cherry picked from commit 8713cca328c9373636efdb92449d743b5bd56584)

diff --git a/doc/glossary.rst b/doc/glossary.rst
index dfe8167d72e29d215ee0e97a0d84e573b2df16b7..0d35c9004721351691fac75170a5576faaced7c8 100644 (file)
--- a/doc/glossary.rst
+++ b/doc/glossary.rst
@@ -15,10 +15,12 @@
                 introduced in the Ceph Kraken release. The Luminous release of
                 Ceph promoted BlueStore to the default OSD back end,
                 supplanting FileStore. As of the Reef release, FileStore is no
-                longer available as a storage backend.
+                longer available as a storage back end.
                 
-                BlueStore stores objects directly on Ceph block devices without
-                a mounted file system.  
+                BlueStore stores objects directly on raw block devices or
+                partitions, and does not interact with mounted file systems.
+                BlueStore uses RocksDB's key/value database to map object names
+                to block locations on disk.
 
         Bucket
                 In the context of :term:`RGW`, a bucket is a group of objects.