clctrl Command

Purpose

Provides a set of system administration functions for managing a cluster.

Syntax

clctrl <subcommand> options

where <subcommand> are {-start | -stop | -tune | -sec | -commit}

Subcommand Syntax

To take a node offline for maintenance or bring it back online:

clctrl [-n clustername]{-start | -stop} [-n clustername]{ -m node[,...] | -a}

To display or set cluster tunable attribute values:

clctrl - tune -h [tunable]

clctrl -tune [-n name | -u uuid] (-a | {-L | -x} [tunable] | {-o tunable})

clctrl -tune [-n name | -u uuid] (-D | {-d tunable} | {-o tunable=value}))

To display or set security tunable values:

clctrl -sec { -l sec_level -s sec_alg } [-e] [ -t certificate_type [-c certificate_file -f privkey_file ]]

To manually commit a new cluster level that is effective throughout the cluster:

clctrl [-n clustername] -commit

Description

The clctrl command provides a set of subcommands for managing a cluster.

The -stop subcommand is used to take one or more nodes offline for maintenance. Stopping a node causes the other nodes to consider it as down. A stopped node does not send or receive heartbeat messages, and it remains in the stopped state, even across reboot operation, until a -start subcommand causes it to rejoin the cluster. The -stop subcommand can also be issued while a node is powered off to prevent it from rejoining the cluster when it is rebooted.

The -start subcommand is used to bring one or more nodes back online after they have been offline for maintenance. Starting a node allows it to rejoin the cluster and have the other nodes consider it as up. The -start subcommand can also be issued while a node is powered off to allow it to rejoin the cluster when it is rebooted.

The -tune subcommand is used to display or set cluster tunable values. The following flags control the -tune subcommand:

Item	Description
-a	Displays values for all tunables, one per line.
-D	Resets all tunables to their default values.
-d tunable	Resets tunable to its default value.
-h	Displays help about the command and its arguments.
-h tunable	Displays help about a tunable.
-L tunable	Lists information about one or all tunables in a table format.
-n name	Specifies the name of the cluster or node entity to which the tunable belongs. The name must be unique. Otherwise, the -u uuid flag must be used to identify the entity.
-o tunable	Displays the current value of a tunable.
-o tunable=value	Sets tunable to the value.
-u uuid	Specifies the UUID of the cluster or node entity. If neither the -u nor the -n options are specified, the invoking node is assumed.
-x tunables	Lists information about one or all tunables in a comma-separated format

The -sec subcommand is used to display or set security tunable values. The following flags control the -sec subcommand:

Item	Description
-c	Specifies the path to the certificate file for the asymmetric key.
-e	Displays values for all security tunables, one per line.
-f	Specifies the path to the private key file for the asymmetric key.
-l	Sets the security level. A value of 0 disables security; a value of 1-3 enables security and sets the level to the value. The default security level is 2.
-s	Specifies the algorithm type used to generate the symmetric key. The value may be set to AES, DES, or 3DES. Setting a value of NULL disables security if it is enabled. The default value is AES.
-t	Specifies the certificate type for the asymmetric key. The value may be set to Self Signed Certificates, Open SSL Certificates, or SSH Certificates. The default value is Self Signed Certificates.

The -commit subcommand manually commits a new cluster level that is effective throughout the cluster, after upgrading the CAA software levels on all nodes. The CAA software automatically commits the new cluster level. However, a system administrator might need to manually commit the new cluster level if the automatic commitment of the new cluster level fails.

Examples

To take a node named fileserver1 offline for maintenance:
```
clctrl -stop -n clustername -m fileserver1
```
To bring the node back online after completing maintenance:
```
  clctrl -start -n clustername -m fileserver1
```
To take all the nodes offline for maintenance:
```
clctrl -stop -n clustername -a
```
To bring all the nodes back online after completing maintenance:
```
clctrl -start -n clustername -a
```
To display information about all cluster tunables in a table format:
```
clctrl -tune -L
```
To display help about tunable repos_mode:
```
clctrl -tune -h repos_mode
```
To set cluster tunables value:
```
clctrl -tune -o repos_mode=e
```
To display the current value of all security tunables:
```
clctrl -sec -e
```
To set the security algorithm used to generate the symmetric key:
```
clctrl -sec -s DES
```
To manually commit a new cluster level that is effective throughout the cluster:
```
clctrl -commit
```
To set the cluster communication mode to the unicast mode:
```
clctrl -tune -o communication_mode=u
```
To set the cluster communication mode to the multicast mode:
```
clctrl -tune -o communication_mode=m
```