initial code repo

[stor4nfv.git] / src / ceph / doc / rbd / iscsi-requirements.rst

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+==========================
+iSCSI Gateway Requirements
+==========================
+
+To implement the Ceph iSCSI gateway there are a few requirements. It is recommended
+to use two to four iSCSI gateway nodes for a highly available Ceph iSCSI gateway
+solution.
+
+For hardware recommendations, see the `Hardware Recommendation page <http://docs.ceph.com/docs/master/start/hardware-recommendations/>`_
+for more details.
+
+.. note::
+    On the iSCSI gateway nodes, the memory footprint of the RBD images
+    can grow to a large size. Plan memory requirements accordingly based
+    off the number RBD images mapped.
+
+There are no specific iSCSI gateway options for the Ceph Monitors or
+OSDs, but it is important to lower the default timers for detecting
+down OSDs to reduce the possibility of initiator timeouts. The following
+configuration options are suggested for each OSD node in the storage
+cluster::
+
+        [osd]
+        osd heartbeat grace = 20
+        osd heartbeat interval = 5
+
+-  Online Updating Using the Ceph Monitor
+
+   ::
+
+       ceph tell <daemon_type>.<id> injectargs '--<parameter_name> <new_value>'
+
+   ::
+
+       ceph tell osd.0 injectargs '--osd_heartbeat_grace 20'
+       ceph tell osd.0 injectargs '--osd_heartbeat_interval 5'
+
+-  Online Updating on the 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 the `Configuration page <http://docs.ceph.com/docs/master/rados/configuration/>`_.