.TH HSCAN 1 2009-03-23 htools "Ganeti H-tools"
.SH NAME
hscan \- Scan clusters via RAPI and save node/instance data

.SH SYNOPSIS
.B hscan
.B "[-p]"
.B "[--no-headers]"
.BI "[-d " path "]"
.I cluster...

.B hscan
.B --version

.SH DESCRIPTION
hscan is a tool for scanning clusters via RAPI and saving their data
in the input format used by
.BR hbal "(1) and " hn1 "(1)."
It will also show a one-line score for each cluster scanned or, if
desired, the cluster state as show by the \fB-p\fR option to the other
tools.

For each cluster, two files named \fIcluster\fB.instances\fR and
\fIcluster\fB.nodes\fR will be generated holding the instance and node
data. These files can then be used in \fBhbal\fR(1) or \fBhn1\fR(1)
via the \fB-i\fR and \fB-n\fR options.

The one-line output for each cluster will show the following:
.RS
.TP
.B Name
The name of the cluster (or the IP address that was given, etc.)
.TP
.B Nodes
The number of nodes in the cluster
.TP
.B Inst
The number of instances in the cluster
.TP
.B BNode
The number of nodes failing N+1
.TP
.B BInst
The number of instances living on N+1-failed nodes
.TP
.B t_mem
Total memory in the cluster
.TP
.B f_mem
Free memory in the cluster
.TP
.B t_disk
Total disk in the cluster
.TP
.B f_disk
Free disk space in the cluster
.TP
.B Score
The score of the cluster, as would be reported by \fBhscan\fR(1) if
run on the generated data files.

.RE

In case of errors while collecting data, all fields after the name of
the cluster are replaced with the error display.

.B Note:
this output format is not yet final so it should not be used for
scripting yet.

.SH OPTIONS
The options that can be passed to the program are as follows:

.TP
.B -p, --print-nodes
Prints the node status for each cluster after the cluster's one-line
status display, in a format designed to allow the user to understand
the node's most important parameters. For details, see the man page
for \fBhbal\fR(1).

.TP
.BI "-d " path
Save the node and instance data for each cluster under \fIpath\fR,
instead of the current directory.

.TP
.B -V, --version
Just show the program version and exit.

.SH EXIT STATUS

The exist status of the command will be zero, unless for some reason
loading the input data failed fatally (e.g. wrong node or instance
data).

.SH BUGS

The program does not check its input data for consistency, and aborts
with cryptic errors messages in this case.

The RAPI collection doesn't deal with non-\fBdrbd\fR instances, and
chokes on input data which has such instances.

.SH EXAMPLE

.in +4n
.nf
.RB "$ " "hscan cluster1"
Name     Nodes  Inst BNode BInst  t_mem  f_mem t_disk f_disk      Score
cluster1     2     2     0     0   1008    652    255    253 0.24404762
.RB "$ " "ls -l cluster1.*"
-rw-r--r-- 1 root root 163 2009-03-23 07:26 cluster1.instances
-rw-r--r-- 1 root root  90 2009-03-23 07:26 cluster1.nodes
.fi
.in

.SH SEE ALSO
.BR hbal "(1), " hn1 "(1), " ganeti "(7), " gnt-instance "(8), " gnt-node "(8)"