ONNODE(1)ONNODE(1)NAMEonnode - run commands on ctdb nodes
SYNOPSISonnode [OPTION] ... NODES COMMAND ...
DESCRIPTIONonnode is a utility to run commands on a specific node of a CTDB
cluster, or on all nodes.
The NODES option specifies which node to run a command on. You can
specify a numeric node number (from 0 to N-1) or a descriptive node
specification (see DESCRIPTIVE NODE SPECIFICATIONS below). You can also
specify lists of nodes, separated by commas, and ranges of numeric node
numbers, separated by dashes. If nodes are specified multiple times
then the command will be executed multiple times on those nodes. The
order of nodes is significant.
The COMMAND can be any shell command. The onnode utility uses ssh or
rsh to connect to the remote nodes and run the command.
DESCRIPTIVE NODE SPECIFICATIONS
The following descriptive node specification can be used in place of
numeric node numbers:
all
All nodes.
any
A node where ctdbd is running. This semi-random but there is a bias
towards choosing a low numbered node.
ok | healthy
All nodes that are not disconnected, banned, disabled or unhealthy.
con | connected
All nodes that are not disconnected.
lvs | lvsmaster
The current LVS master.
natgw | natgwlist
The current NAT gateway.
rm | recmaster
The current recovery master.
OPTIONS-c
Execute COMMAND in the current working directory on the specified
nodes.
-o <prefix>
Causes standard output from each node to be saved into a file with
name <prefix>.<ip>.
-p
Run COMMAND in parallel on the specified nodes. The default is to
run COMMAND sequentially on each node.
-q
Do not print node addresses. Normally, onnode prints informational
node addresses if more than one node is specified. This overrides
-v.
-n
Allow nodes to be specified by name rather than node numbers. These
nodes don´t need to be listed in the nodes file. You can avoid the
nodes file entirely by combining this with -f /dev/null.
-f <file>
Specify an alternative nodes file to use instead of the default.
This option overrides the CTDB_NODES_FILE environment variable. See
the discussion of /etc/ctdb/nodes in the FILES section for more
details.
-v
Print a node addresses even if only one node is specified.
Normally, onnode prints informational node addresses when more than
one node is specified.
-h, --help
Show a short usage guide.
EXAMPLES
The following command would show the process ID of ctdb on all nodes
onnode all pidof ctdbd
The following command would show the last 5 lines of log on each node,
preceded by the node´s hostname
onnode all "hostname; tail -5 /var/log/log.ctdb"
The following command would restart the ctdb service on all nodes.
onnode all service ctdb restart
The following command would run ./foo in the current working directory,
in parallel, on nodes 0, 2, 3 and 4.
onnode-c -p 0,2-4 ./foo
ENVIRONMENT
CTDB_NODES_FILE
Name of alternative nodes file to use instead of the default. See
the discussion of /etc/ctdb/nodes in the FILES section for more
details.
FILES
/etc/ctdb/nodes
Default file containing a list of each node´s IP address or
hostname.
Actually, the default is $CTDB_BASE/nodes, where $CTDB_BASE
defaults to /etc/ctdb. If a relative path is given (via the -f
option or $CTDB_BASE) and no corresponding file exists relative to
the current directory then the file is also searched for in the
$CTDB_BASE directory.
/etc/ctdb/onnode.conf
If this file exists it is sourced by onnode. The main purpose is to
allow the administrator to set $SSH to something other than "ssh".
In this case the -t option is ignored. For example, the
administrator may choose to use use rsh instead of ssh.
SEE ALSOctdbd(1), ctdb(1), http://ctdb.samba.org/
COPYRIGHT/LICENSE
Copyright (C) Andrew Tridgell 2007
Copyright (C) Ronnie sahlberg 2007
Copyright (C) Martin Schwenke 2008
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or (at
your option) any later version.
This program is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, see http://www.gnu.org/licenses/.
02/05/2010 ONNODE(1)
