NAME
cman_tool - Cluster Management Tool
SYNOPSIS
cman_tool join | leave | kill | expected | votes | version | wait | status | nodes | services | debug [options]
DESCRIPTION
cman_tool
is a program that manages the cluster management subsystem CMAN. cman_tool
can be used to join the node to a cluster, leave the cluster, kill another
cluster node or change the value of expected votes of a cluster.
Be careful that you understand the consequences of the commands issued via cman_tool
as they can affect all nodes in your cluster. Most of the time the cman_tool
will only be invoked from your startup and shutdown scripts.
SUBCOMMANDS
join
This is the main use of cman_tool. It instructs the cluster manager to attempt
to join an existing cluster or (if no existing cluster exists) then to form
a new one on its own.
If no options are given to this command then it will take the cluster
configuration information from CCS. However, it is possible to provide
all the information on the command-line or to override CCS values by using
the command line.
leave
Tells CMAN to leave the cluster. You cannot do this if there are subsystems
(eg DLM, GFS) active. You should dismount all GFS filesystems,
shutdown CLVM, fenced and anything else using the cluster manager before
using
cman_tool leave.
Look at 'cman_tool status' and group_tool to see how many (and which)
subsystems are active.
When a node leaves the cluster, the remaining nodes recalculate quorum and this
may block cluster activity if the required number of votes is not present.
If this node is to be down for an extended period of time and you need to
keep the cluster running, add the
remove
option, and the remaining nodes will recalculate quorum such that activity
can continue.
kill
Tells CMAN to kill another node in the cluster. This will cause the local
node to send a "KILL" message to that node and it will shut down. Recovery
will occur for the killed node as if it had failed. This is a sort of remote
version of "leave force" so only use if if you really know what you are doing.
expected
Tells CMAN a new value of expected votes and instructs it to recalculate
quorum based on this value.
Use this option if your cluster has lost quorum due to nodes failing and
you need to get it running again in a hurry.
version
Used alone this will report the major, minor, patch and config versions
used by CMAN (also displayed in 'cman_tool status'). It can also be used
with -r to set a new config version on all cluster members.
wait
Waits until the node is a member of the cluster and then returns.
status
Displays the local view of the cluster status.
nodes
Displays the local view of the cluster nodes.
services
Displays the local view of subsystems using cman (deprecated, group_tool
should be used instead).
debug
Sets the debug level of the running cman daemon. Debug output will be
sent to syslog level LOG_DEBUG. the
-d
switch specifies the new logging level. This is the same bitmask used
for cman_tool join -d
-w
Normally, "cman_tool leave" will fail if the cluster is in transition (ie
another node is joining or leaving the cluster). By adding the -w flag,
cman_tool will wait and retry the leave operation repeatedly until it succeeds
or a more serious error occurs.
-t <seconds>
If -w is also specified then -t dictates the maximum amount of time cman_tool
is prepared to wait. If the operation times out then a status of 2 is returned.
force
Shuts down the cluster manager without first telling any of the subsystems
to close down. Use this option with extreme care as it could easily cause data
loss.
remove
Tells the rest of the cluster to recalculate quorum such that activity can
continue without this node.
-e <expected-votes>
The new value of expected votes to use. This will usually be enough
to bring the cluster back to life. Values that would cause incorrect
quorum will be rejected.
-n <nodename>
The node name of the node to be killed. This should be the unqualified node
name as it appears in 'cman_tool nodes'.
-r <config_version>
The new config version. You don't need to use this when adding a new node,
the new cman node will tell the rest of the cluster to get their latest
version of the config file from CCS automatically.
-q
Waits until the cluster is quorate before returning.
-t <seconds>
Dictates the maximum amount of time cman_tool is prepared to wait.
If the operation times out then a status of 2 is returned.
-c <clustername>
Provides a text name for the cluster. You can have several clusters on one
LAN and they are distinguished by this name. Note that the name is hashed to
provide a unique number which is what actually distinguishes the cluster, so
it is possible that two different names can clash. If this happens, the node
will not be allowed into the existing cluster and you will have to pick
another name or use different port number for cluster communication.
-p <port>
UDP port number used for cluster communication. This defaults to 5405.
-v <votes>
Number of votes this node has in the cluster. Defaults to 1.
-e <expected votes>
Number of expected votes for the whole cluster. If different nodes
provide different values then the highest is used. The cluster will
only operate when quorum is reached - that is more than half the
available votes are available to the cluster. There is no default for
this value. If you are using CCS then ccs_tool will use the total
number of votes for all nodes in the configuration file.
-2
Sets the cluster up for a special "two node only" mode. Because of the
quorum requirements mentioned above, a two-node cluster cannot be valid.
This option tells the cluster manager that there will only ever be two
nodes in the cluster and relies on fencing to ensure cluster integrity.
If you specify this you cannot add more nodes without taking down the
existing cluster and reconfiguring it. Expected votes should be set to
1 for a two-node cluster.
-n <nodename>
Overrides the node name. By default the unqualified hostname is used. This
option can also be used to specify which interface is used for cluster
communication as cman_tool will (unless multicast is specified below)
use the broadcast address associated with that hostname. If you
are using IPv6 then you will have to use multicast rather than broadcast.
-N <nodeid>
Overrides the node ID for this node. Normally, nodes are assigned a
node id in CCS. If you specify an incorrect node ID here, the
node might not be allowed to join the cluster.
-o <nodename>
Override the name this node will have in the cluster. This will
normally be the hostname or the first name specified by -n.
Note how this differs from -n: -n tells cman_tool how to find
the broadcast address and/or the entry in CCS. -o simply
changes the name the node will have in the cluster and has no
bearing on the actual name of the machine. Use this option
will extreme caution.
R
Setting node IDs in CCS is a far better way to do this though.
R
Note that the node's application to join the cluster may be rejected if you
try to set the nodeid to one that has already been used, or if the node
was previously a member of the cluster but with a different nodeid.
-m <multicast-address>
Specifies a multicast address to use for cluster communication. This
is required for IPv6 operation. You should also specify an ethernet
interface to bind to this multicast address using the -i option.
-w
Join and wait until the node is a cluster member.
-q
Join and wait until the cluster is quorate.
If the cluster join fails and -w (or -q) is specified, then it will be retried. Note that
cman_tool cannot tell whether the cluster join was rejected by another node for a good reason
or that it timed out for some benign reason; so it is strongly recommended that a timeout
is also given with the wait options to join. If you don't want join to retry on failure but
do want to wait, use the
cman_tool join
command without -w followed by
cman_tool wait.
-k <keyfile>
All traffic sent out by cman/openais is encrypted. By default the security key
used is simply the cluster name. If you need more security you can specify a
key file that contains the key used to encrypt cluster communications.
Of course, the contents of the key file must be the same on all nodes in the
cluster. It is up to you to securely copy the file to the nodes.
-t <seconds>
If -w or -q is also specified then -t dictates the maximum amount of time cman_tool
is prepared to wait. If the operation times out then a status of 2 is returned.
Note that just because cman_tool has given up, does not mean that cman itself
has stopped trying to join a cluster.
-f
Shows the date/time the node was last fenced (if it has bee fenced), and also
the fence system that was used.
-a
Shows the IP address(es) the nodes are communicating on.
-n <nodename>
Shows node information for a specific node. This should be the unqualified node
name as it appears in 'cman_tool nodes'.
-F <format>
Specify the format of the output. The format string may contain one or
more format options, each seperated by a comma. Valid format options
include: id, name, type, and addr.
-d <value>
The value is a bitmask of
2 Barriers
4 Membership messages
8 Daemon operation, including command-line interaction
16 Interaction with OpenAIS