.TH "ocfs2_hb_ctl" "8" "January 2012" "Version 1.8.7" "OCFS2 Manual Pages"
.SH "NAME"
ocfs2_hb_ctl \- Starts and stops the \fIO2CB\fR \fBlocal\fR heartbeat on a given device.
.SH "SYNOPSIS"

.B ocfs2_hb_ctl
\fB-S\fR \fB-d\fR \fIdevice\fR \fIservice\fR
.br
.B ocfs2_hb_ctl
\fB-S\fR \fB-u\fR \fIuuid\fR \fIservice\fR
.br
.B ocfs2_hb_ctl
\fB-K\fR \fB-d\fR \fIdevice\fR \fIservice\fR
.br
.B ocfs2_hb_ctl
\fB-K\fR \fB-u\fR \fIuuid\fR \fIservice\fR
.br
.B ocfs2_hb_ctl
\fB-I\fR \fB-d\fR \fIdevice\fR
.br
.B ocfs2_hb_ctl
\fB-I\fR \fB-u\fR \fIuuid\fR
.br
.B ocfs2_hb_ctl
\fB-P\fR \fB-d\fR \fIdevice\fR [\fB-n\fR \fIio_priority\fR]
.br
.B ocfs2_hb_ctl
\fB-P\fR \fB-u\fR \fIuuid\fR [\fB-n\fR \fIio_priority\fR]
.br
.B ocfs2_hb_ctl
\fB-h\fI
.br

.SH "DESCRIPTION"
.PP 
\fBocfs2_hb_ctl\fR starts and stops \fBlocal\fR heartbeat on a \fIOCFS2\fR device.
\fBUsers are strongly urged not to use this tool directly\fR. It is automatically
invoked by \fBmount.ocfs2(8)\fR and other tools that require heartbeat notifications.

This utility only operates in the \fBlocal\fR heartbeat mode. It fails silently
when run in \fBglobal\fR heartbeat mode. More information on the heartbeat modes
can be found in \fBo2cb(7)\fR.

The tools accepts devices to be specified by its name or its uuid. Service denotes
the application that is requesting the heartbeat notification.

.SH "OPTIONS"
.TP
\fB\-S\fR
Starts the heartbeat.

.TP
\fB\-K\fR
Stops the heartbeat.

.TP
\fB\-I\fR
Prints the heartbeat reference counts for that heartbeat region.

.TP
\fB\-d\fR
Specify region by device name.

.TP
\fB\-u\fR
Specify region by device uuid.

.TP
\fB\-n\fR
Adjust IO priority for the heartbeat thread. This option calls the \fBionice\fR
tool to set its IO scheduling class to realtime with scheduling class data as provided.
This option is usable only with the \fBO2CB\fR cluster stack.

.TP
\fB\-h\fR
Displays help and exit.

.SH "SEE ALSO"
.BR mount.ocfs2(8)
.BR o2cb(7)
.BR o2cb(8)
.BR o2cb.sysconfig(5)
.BR ocfs2.cluster.conf(5)
.BR o2cluster(8)

.SH "AUTHORS"
Oracle Corporation

.SH "COPYRIGHT"
Copyright \(co 2004, 2012 Oracle. All rights reserved.