Add a man page for hsqueeze

Describe the current state of the Ganeti dynamic power management
tool, hsqueeze, in a man page.
Signed-off-by: Klaus Aehlig <aehlig@google.com>
Reviewed-by: Michele Tartara <mtartara@google.com>

Makefile.am

@@ -1210,6 +1210,7 @@ man_MANS = \
 	man/hinfo.1 \
 	man/hscan.1 \
 	man/hspace.1 \
+	man/hsqueeze.1 \
 	man/hroller.1 \
 	man/htools.1 \
 	man/mon-collector.7

man/hsqueeze.rst

+HSQUEEZE(1) Ganeti | Version @GANETI_VERSION@
+=============================================
+
+NAME
+----
+
+hsqueeze \- Dynamic power management
+
+SYNOPSIS
+--------
+
+**hsqueeze** {backend options...} [algorithm options...] [reporting options...]
+
+**hsqueeze** \--version
+
+Backend options:
+
+{ **-L[** *path* **]** | **-t** *data-file* }
+
+Algorithm options:
+
+**[ \--target-resources=*factor* ]**
+
+Reporting options:
+
+**[ -S *file* ]**
+
+
+DESCRIPTION
+-----------
+
+hsqueeze does dynamic power management, by powering up or shutting down nodes,
+depending on the current load of the cluster. Currently, only suggesting nodes
+to be powered off is implemented.
+
+ALGORITHM
+~~~~~~~~~
+
+hsqueeze considers all online non-master nodes with only externally mirrored
+instances as candidates for being taken offline. These nodes are iteratively,
+starting from the node with the least number of instances, added to the set
+of nodes to be put offline, if possible. A set of nodes is considered as suitable
+for being taken offline, if, after marking these nodes as offline, balancing the
+cluster by the algorithm used by **hbal**\(1) yields a situation where all instances
+are located on online nodes, and each node has at least the target resources free
+for new instances.
+
+OPTIONS
+-------
+
+-L [*path*]
+  Backend specification: collect data directly from the master daemon,
+  which is to be contacted via LUXI (an internal Ganeti protocol). The
+  option is described in the man page **htools**\(1).
+
+-S *filename*, \--save-cluster=*filename*
+  If given, the state of the cluster before the squeezing is saved to
+  the given file plus the extension "original"
+  (i.e. *filename*.original), and the state at the end of the
+  squeezing operation is saved to the given file plus the extension "squeezed"
+  (i.e. *filename*.squeezed).
+
+-t *datafile*, \--text-data=*datafile*
+  Backend specification: the name of the file holding node and instance
+  information (if not collecting LUXI). This or one of the
+  other backends must be selected. The option is described in the man
+  page **htools**\(1).
+
+\--target-resources=*factor*
+  Specify the amount of resources to remain free on any node after squeezing.
+  The value is reported a multiple of the standard instance specification, as
+  taken from the instance policy.