With the -g option followed by host group name, msgblock tries to lock the host in the host group. With the -f option followed by a filename, msgblock tries to lock the hosts listed in the file.

Unlike the scrun(1) command, msgblock locks the Compute Host Lock Server msgbserv(8) with yellow color which users can see via msgb(1) command. The other colors can be specified by the option -color> followed by pink, orange, green, cyan, purple, wheat and gray.

The options available for msgblock:

-n N

msgblock tries to lock N hosts out of the specified host group or the host list file. When some hosts in the host list are locked, then msgblock searches free (unlocked) N contigeous hosts from the list.

-nc

With the combination of the -n option, msgblock searches free (unlocked) N hosts which may not be contigeous.

-machinefile filename
-ofile filename
-of filename

When the free host search is succeeded, msgblock output the host list to the file sepcified by the filename.

-smp N
-cpu N

With the combination of the -machinefile option, msgblock creates the file which contains lines of hostnames followed by semi-colon (:) and the specified number N.

-n

When specified, the sceptic command outputs the list of host which are responding.

-wait

When specified, msgblock periodically tries to lock the specified hosts until it succeeds.