Adding upstream version 18.2.2.upstream/18.2.2

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 51 insertions, 0 deletions

diff --git a/doc/rbd/iscsi-requirements.rst b/doc/rbd/iscsi-requirements.rst
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+==========================
+iSCSI Gateway Requirements
+==========================
+
+It is recommended to provision two to four iSCSI gateway nodes to
+realize a highly available Ceph iSCSI gateway solution.
+
+For hardware recommendations, see :ref:`hardware-recommendations` .
+
+.. note::
+    On iSCSI gateway nodes the memory footprint is a function of
+    of the RBD images mapped and can grow to be large. Plan memory
+    requirements accordingly based on the number RBD images to be mapped.
+
+There are no specific iSCSI gateway options for the Ceph Monitors or
+OSDs, but it is important to lower the default heartbeat interval for
+detecting down OSDs to reduce the possibility of initiator timeouts.
+The following configuration options are suggested::
+
+        [osd]
+        osd heartbeat grace = 20
+        osd heartbeat interval = 5
+
+-   Updating Running State From a Ceph Monitor Node
+
+   ::
+
+       ceph tell <daemon_type>.<id> config set <parameter_name> <new_value>
+
+   ::
+
+       ceph tell osd.* config set osd_heartbeat_grace 20
+       ceph tell osd.* config set osd_heartbeat_interval 5
+
+-  Updating Running State On Each OSD Node
+
+   ::
+
+       ceph daemon <daemon_type>.<id> config set osd_client_watch_timeout 15
+
+   ::
+
+       ceph daemon osd.0 config set osd_heartbeat_grace 20
+       ceph daemon osd.0 config set osd_heartbeat_interval 5
+
+For more details on setting Ceph's configuration options, see
+:ref:`configuring-ceph`.  Be sure to persist these settings in
+``/etc/ceph.conf`` or, on Mimic and later releases, in the
+centralized config store.
+
+