hbal: Early exit when we don't have any instances

[ganeti-local] / hbal.1

diff --git a/hbal.1 b/hbal.1
index 2d98c95..da58ebe 100644 (file)
--- a/hbal.1
+++ b/hbal.1
@@ -9,6 +9,7 @@ hbal \- Cluster balancer for Ganeti
 .B "[-o]"
 .BI "[-l" limit "]"
 .BI "[-O" name... "]"
+.BI "[-e" score "]"
 .BI "[-m " cluster "]"
 .BI "[-n " nodes-file " ]"
 .BI "[-i " instances-file "]"
@@ -248,18 +249,35 @@ the percentage of instances on offline nodes)
 .RE
 
 .TP
+.BI "-e" score ", --min-score=" score
+This parameter denotes the minimum score we are happy with and alters
+the computation in two ways:
+.RS
+.RS 4
+.TP 3
+\(em
+if the cluster has the initial score lower than this value, then we
+don't enter the algorithm at all, and exit with success
+.TP
+\(em
+during the iterative process, if we reach a score lower than this
+value, we exit the algorithm
+.RE
+The default value of the parameter is currently \fI1e-9\fR (chosen
+empirically).
+.RE
+
+.TP
 .BI "-n" nodefile ", --nodes=" nodefile
 The name of the file holding node information (if not collecting via
-RAPI), instead of the default
-.I nodes
-file.
+RAPI), instead of the default \fInodes\fR file (but see below how to
+customize the default value via the environment).
 
 .TP
 .BI "-i" instancefile ", --instances=" instancefile
 The name of the file holding instance information (if not collecting
-via RAPI), instead of the default
-.I instances
-file.
+via RAPI), instead of the default \fIinstances\fR file (but see below
+how to customize the default value via the environment).
 
 .TP
 .BI "-m" cluster
@@ -288,6 +306,13 @@ Just show the program version and exit.
 The exist status of the command will be zero, unless for some reason
 the algorithm fatally failed (e.g. wrong node or instance data).
 
+.SH ENVIRONMENT
+
+If the variables \fBHTOOLS_NODES\fR and \fBHTOOLS_INSTANCES\fR are
+present in the environment, they will override the default names for
+the nodes and instances files. These will have of course no effect
+when RAPI is used.
+
 .SH BUGS
 
 The program does not check its input data for consistency, and aborts