svn commit: r47606 - head/en_US.ISO8859-1/htdocs/news/status

Sat Oct 17 21:08:48 UTC 2015

Author: bjk
Date: Sat Oct 17 21:08:46 2015
New Revision: 47606
URL: https://svnweb.freebsd.org/changeset/doc/47606

Log:
  Add CTL HA report from mav

Modified:
  head/en_US.ISO8859-1/htdocs/news/status/report-2015-07-2015-09.xml

Modified: head/en_US.ISO8859-1/htdocs/news/status/report-2015-07-2015-09.xml
==============================================================================

--- head/en_US.ISO8859-1/htdocs/news/status/report-2015-07-2015-09.xml	Sat Oct 17 19:19:43 2015	(r47605)
+++ head/en_US.ISO8859-1/htdocs/news/status/report-2015-07-2015-09.xml	Sat Oct 17 21:08:46 2015	(r47606)
@@ -2299,4 +2299,60 @@
     </help>
   </project>
 
+  <project cat='proj'>
+    <title>High Availability clustering in CTL</title>
+
+    <contact>
+      <person>
+	<name>
+	  <given>Alexander</given>
+	  <common>Motin</common>
+	</name>
+	<email>mav at FreeBSD.org</email>
+      </person>
+    </contact>
+
+    <body>
+      <p>CAM Target Layer (CTL), when originally developed by
+	Copan/SGI, had support for High Availability clustering.
+	Unfortunately, significant portions of the HA code were never
+	published with the main body of the source code.  Now, the missing
+	part has been reimplemented from scratch and fixed/improved.</p>
+
+      <p>This code supports dual-node HA with Asynchronous LUN Unit
+	Access (ALUA) in four modes:</p>
+
+      <ul>
+	<li>Active/Unavailable without interlink between nodes, where
+	  the secondary node can report nothing except its presence.</li>
+	<li>Active/Standby with secondary node handling only basic LUN
+	  discovery and reservation, synchronizing state and command
+	  execution with the primary node through the interlink.</li>
+	<li>Active/Active with both nodes processing commands and
+	  accessing the backing storage, synchronizing state and command
+	  execution with the primary node through the interlink.</li>
+	<li>Active/Active with secondary node having no backing storage
+	  access, but instead working as a proxy, transfering all commands
+	  to the first node for execution through the interlink.</li>
+      </ul>
+
+      <p>In the case of lost interlink connectivity to primary node,
+	the secondary node falls into the Transitioning state, which is
+	like Unavailable and can't answer most requests, but makes the
+	initiator wait for recovery or cluster failover.</p>
+
+      <p>CTL also got a large number of other improvements, including
+	support for emulation of CD/DVD drives and removable disks,
+	live LUN reconfiguration, etc.</p>
+
+      <p>The code is committed to &os; head and was recently merged to
+	stable/10 branch.
+      </p>
+    </body>
+
+    <sponsor>
+      iXsystems, Inc.
+    </sponsor>
+  </project>
+
 </report>
