mmchnode command

Changes node attributes.

Synopsis

mmchnode change-options -N {Node[,Node...] | NodeFile | NodeClass} 
     [--cloud-gateway-nodeclass CloudGatewayNodeClass]

mmchnode {-S Filename | --spec-file=Filename}

Availability

Available on all IBM Storage Scale editions.

Description

Use the mmchnode command to change one or more attributes on a single node or on a set of nodes. If conflicting node designation attributes are defined for a specified node, the last value is used. If any of the attributes represent a node-unique value, the -N option must resolve to a single node.

Do not use the mmchnode command to change the gateway node role while IO is happening on the fileset. Run the flushpending command to flush any pending messages from queues before you run the mmchnode command for the gateway node role changes.

Note: When you change quorum designations for a node, if the IBM Storage Scale native REST API feature is enabled, restart scaleadmd on the nodes where the quorum has changed.

Parameters

-N {Node[,Node...] | NodeFile | NodeClass}

Specifies the nodes whose states are to be changed.

For general information on how to specify node names, see Specifying nodes as input to GPFS commands.

[--cloud-gateway-nodeclass CloudGatewayNodeClass]

Use this option to specify a node class that you use for transparent cloud tiering management along with the -N option where you specify individual node names. Both -N with a node list and --cloud-gateway-node with a node class are required.

-S Filename | --spec-file=Filename

Specifies a file with a detailed description of the changes to be made. Each line represents the changes to an individual node and has the following format:

node-identifier change-options

change-options

A blank-separated list of attribute[=value] pairs. The following attributes can be specified:

--admin-interface={hostname | ip_address}

Specifies the name of the node to be used by GPFS administration commands when it is communicating between nodes. The admin node name must be specified as an IP address or a hostname that is resolved by the host command to the appropriate IP address. If the keyword DEFAULT is specified, the admin interface for the node is set to be equal to the existing daemon interface for the node. If --admin-interface=DEFAULT is specified and at the same time a new host name is specified for --daemon-interface option, then the admin interface for the node is set to the existing value that is specified for --daemon-interface and not the new value provided with the command.

--client

Specifies that the node must not be part of the pool of nodes from which cluster managers, file system managers, and token managers are selected.

--cloud-gateway-enable

Enables one or more nodes as transparent cloud tiering nodes on the cluster based on the -N option parameters.

--cloud-gateway-disable

Disables one or more transparent cloud tiering nodes from the cluster based on the -N option parameters. Disable a transparent cloud tiering node only if you no longer need it to migrate or recall data from the configured cloud.

--ces-enable

Enables Cluster Export Services (CES) on the node.

--ces-disable

Disables CES on the node.

--ces-group=Group[,Group...]

Adds one or more groups to the specified nodes. Each group that is listed is added to all the specified nodes.

--noces-group=Group[,Group...]

Removes one or more groups from the specified nodes.

--cnfs-disable

Disables the CNFS function of a CNFS member node.

--cnfs-enable

Enables a previously disabled CNFS member node.

--cnfs-groupid=groupid

Specifies a failover recovery group for the node. If the keyword DEFAULT is specified, the CNFS recovery group for the node is set to zero.

For more information, see Implementing a clustered NFS environment on Linux.

--cnfs-interface=ip_address_list

A comma-separated list of hostnames or IP addresses to be used for GPFS cluster NFS serving.

The specified IP addresses can be real or virtual (aliased). These addresses must be configured to be static (not DHCP) and to not start at boot time.

The GPFS daemon interface for the node cannot be a part of the list of CNFS IP addresses.

If the keyword DEFAULT is specified, the CNFS IP address list is removed and the node is no longer considered a member of CNFS.

If adminMode central is in effect for the cluster, all CNFS member nodes must be able to run remote commands without the need for a password.

For more information, see Implementing a clustered NFS environment on Linux.

--comment

Provides additional information on the node.

Note:

Comments can only contain the following characters:
0-9 A-Z a-z (space) # - . @ _
While running a command with the --comment option and also when using a Filename or --specFile option, all comments that include one or more spaces must be enclosed within single quotation marks (') or double quotation marks ("). You must always use quotation marks with comments to avoid possible parsing errors.
Comments must not begin with a -.
Comments cannot be longer than 32 characters.
Comments that include spaces at the beginning or end will have the spaces trimmed.

The comment field adds new data that is stored in the cluster configuration file and is available only to nodes running on IBM Storage Scale 5.1.4 or later for reading and configuring.

--daemon-interface={hostname | ip_address}

Specifies the host name or IP address to be used by the GPFS daemons for node-to-node communication. The host name or IP address must refer to the communication adapter over which the GPFS daemons communicate. Aliased interfaces are not allowed. Use the original address or a name that is resolved by the host command to the original address. You cannot set --daemon-interface=DEFAULT.

You must stop all the nodes in the cluster with mmshutdown before you set this attribute. This requirement holds true even if you are changing only one node.

See examples 8 and 9.

If the minimum release level of the cluster is IBM Storage Scale 5.1.0 or later, the following features are available:

You can specify the --daemon-interface option for a quorum node even when CCR is enabled. For earlier versions of IBM Storage Scale do the following steps:
1. Temporarily change the quorum node to a nonquorum node.
2. Issue the mmchnode command with the --daemon-interface option for the nonquorum node.
3. Change the nonquorum node back to a quorum node.
You can change the IP addresses or host names of cluster nodes when a node quorum is not available. For more information, see Changing IP addresses or host names of cluster nodes.

--gateway | --nogateway

Specifies whether the node is to be designated as a gateway node or not.

--manager | --nomanager

Designates the node as part of the pool of nodes from which file system managers and token managers are selected.

--nonquorum

Designates the node as a non-quorum node. If two or more quorum nodes are downgraded at the same time, GPFS must be stopped on all nodes in the cluster. GPFS does not have to be stopped if the nodes are downgraded one at a time.

--perfmon | --noperfmon

Specifies whether the node is to be designated as a perfmon node or not.

--nosnmp-agent

Stops the SNMP subagent and specifies that the node must no longer serve as an SNMP collector node. For more information, see GPFS SNMP support.

--quorum

Designates the node as a quorum node.

Note: If you are designating a node as a quorum node, and adminMode central is in effect for the cluster, you must ensure that GPFS is up and running on that node. The mmgetstate command reports the state of the node as active.

--snmp-agent

Designates the node as an SNMP collector node. If the GPFS daemon is active on this node, the SNMP subagent is started as well. For more information, GPFS SNMP support.

Exit status

0: Successful completion.
nonzero: A failure occurred.

Security

You must have root authority to run the mmchnode command.

The node on which the command is issued must be able to run remote shell commands on any other node in the cluster without the use of a password and without producing any extraneous messages. For more information, see Requirements for administering a GPFS file system.

Examples

To change nodes k145n04 and k145n05 to be both quorum and manager nodes, issue the following command:

# mmchnode --quorum --manager -N k145n04,k145n05

A sample output is as follows:

Wed May 16 04:50:24 EDT 2007: mmchnode: Processing node k145n04.kgn.ibm.com
Wed May 16 04:50:24 EDT 2007: mmchnode: Processing node k145n05.kgn.ibm.com
mmchnode: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

After completion, mmlscluster displays information similar to:

GPFS cluster information
========================
GPFS cluster name: mynodes.kgn.ibm.com
GPFS cluster id: 680681553700098206
GPFS UID domain: mynodes.kgn.ibm.com
Remote shell command: /usr/bin/ssh
Remote file copy command: /usr/bin/scp

GPFS cluster configuration servers:
-----------------------------------
Primary server: k145n04.kgn.ibm.com
Secondary server: k145n06.kgn.ibm.com

Node Daemon node name  IP address  Admin node name     Designation
---------------------------------------------------------------------
1  k145n04.kgn.ibm.com 9.114.68.68 k145n04.kgn.ibm.com quorum-manager
2  k145n05.kgn.ibm.com 9.114.68.69 k145n05.kgn.ibm.com quorum-manager
3  k145n06.kgn.ibm.com 9.114.68.70 k145n06.kgn.ibm.com

To change nodes k145n04 and k145n05 to be both quorum and manager nodes, and node k45n06 to be a non-quorum node, issue the following command:

# mmchnode -S /tmp/specFile

Where the contents of /tmp/specFile are:

k145n04 --quorum --manager
k145n05 --quorum --manager
k145n06 --nonquorum

A sample output is as follows:

Wed May 16 05:23:31 EDT 2007: mmchnode: Processing node k145n04
Wed May 16 05:23:32 EDT 2007: mmchnode: Processing node k145n05
Wed May 16 05:23:32 EDT 2007: mmchnode: Processing node k145n06
Verifying GPFS is stopped on all nodes ...
mmchnode: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

And mmlscluster displays information similar to:

GPFS cluster information
========================
GPFS cluster name: mynodes.kgn.ibm.com
GPFS cluster id: 680681553700098206
GPFS UID domain: mynodes.kgn.ibm.com
Remote shell command: /usr/bin/rsh
Remote file copy command: /usr/bin/rcp

GPFS cluster configuration servers:
-----------------------------------
Primary server: k145n04.kgn.ibm.com
Secondary server: k145n06.kgn.ibm.com

Node Daemon node name   IP address   Admin node name     Designation
-----------------------------------------------------------------------
1  k145n04.kgn.ibm.com  9.114.68.68  k145n04.kgn.ibm.com quorum-manager
2  k145n05.kgn.ibm.com  9.114.68.69  k145n05.kgn.ibm.com quorum-manager
3  k145n06.kgn.ibm.com  9.114.68.70  k145n06.kgn.ibm.com

To enable all the nodes that are specified in the node class TCTNodeClass1 as transparent cloud tiering nodes, issue the following command:

# mmchnode --cloud-gateway-enable -N TCTNodeClass1

A sample output is as follows:


Wed May 11 12:51:37 EDT 2016: mmchnode: Processing node c350f2u18
mmchnode: Verifying media for Transparent Cloud Tiering nodes...
mmchnode: node c350f2u18 media checks passed.

Wed May 11 12:51:38 EDT 2016: mmchnode: Processing node c350f2u22.pk.labs.ibm.com
mmchnode: node c350f2u22.pok.stglabs.ibm.com media checks passed.

Wed May 11 12:51:41 EDT 2016: mmchnode: Processing node c350f2u26.pk.labs.ibm.com
mmchnode: node c350f2u26.pok.stglabs.ibm.com media checks passed.

mmchnode: Propagating the cluster configuration data to all
affected nodes.  This is an asynchronous process.

You can verify the transparent cloud tiering nodes by issuing the following command:

# mmcloudgateway node list

To designate only a few nodes (node1 and node2) in the node class, TCTNodeClass1, as transparent cloud tiering server nodes, issue the following command:
```
# mmchnode --cloud-gateway-enable -N node1,node2 --cloud-gateway-nodeclass TCTNodeClass1
```
Note: It only designates node1 and node2 as transparent cloud tiering server nodes from the node class, TCTNodeClass1. Administrators can continue to use the node class for other purposes.

To disable all transparent cloud tiering nodes from the node class, TCTNodeClass1, issue the following command:

# mmchnode --cloud-gateway-disable -N TCTNodeClass1

A sample output is as follows:


Thu May 12 16:10:11 EDT 2016: mmchnode: Processing node c350f2u18
mmchnode: Verifying Transparent Cloud Tiering node c350f2u18 can be disabled...
mmchnode: Node c350f2u18 passed disable checks.

Thu May 12 16:10:11 EDT 2016: mmchnode: Processing node c350f2u22.pk.labs.ibm.com
mmchnode: Verifying Transparent Cloud Tiering node c350f2u22.pk.labs.ibm.com can be disabled...
mmchnode: Node c350f2u22.pok.stglabs.ibm.com passed disable checks.

Thu May 12 16:10:14 EDT 2016: mmchnode: Processing node c350f2u26.pk.labs.ibm.com
mmchnode: Verifying Transparent Cloud Tiering node c350f2u26.pk.labs.ibm.com can be disabled...
mmchnode: Node c350f2u26.pk.labs.ibm.com passed disable checks.

mmchnode: Propagating the cluster configuration data to all
affected nodes.  This is an asynchronous process.

To disable only a few nodes (node1 and node2) from the node class, TCTNodeClass1, as transparent cloud tiering server nodes, issue the following command:
```
# mmchnode --cloud-gateway-disable -N node1,node2 --cloud-gateway-nodeclass TCTNodeClass1
```
Note: It only disables node1 and node2 as transparent cloud tiering server nodes from the node class, TCTNodeClass1.

To add groups to specified nodes, issue the mmchnode --ces-group command. For example,

# mmchnode --ces-group g1,g2 -N 2,3

Note: This command adds groups g1 and g2 to both nodes 2 and 3. Run the mmces node list command to view the group allocation:


[root@cluster-12 ~]# mmces node list
Node   Name                      Node Groups   Node Flags   
------ ------------------------- ------------- ------------ 
2      cluster-12.localnet.com   g1,g2         Suspended    
3      cluster-13.localnet.com   g1,g2         none         
4      cluster-14.localnet.com                 none

The following example changes the daemon interface of a cluster node:

The mmlscluster command displays the state of the cluster:

# mmlscluster
GPFS cluster information
========================
  GPFS cluster name:         small_cluster.localnet.com
  GPFS cluster id:           5072947464461061246
  GPFS UID domain:           small_cluster.localnet.com
  Remote shell command:      /usr/bin/ssh
  Remote file copy command:  /usr/bin/scp
  Repository type:           CCR
GPFS cluster configuration servers:
-----------------------------------
  Primary server:    node-6.localnet.com (not in use)
  Secondary server:  (none)
 Node  Daemon node name     IP address      Admin node name      Designation
-----------------------------------------------------------------------------
   1   node-6.localnet.com  192.168.124.36  node-6.localnet.com  quorum
   2   node-7.localnet.com  192.168.124.37  node-7.localnet.com  quorum
   3   node-8.localnet.com  192.168.124.38  node-8.localnet.com

The mmchnode command changes the daemon interface of node-6 from node-6.localnet.com/192.168.124.36 to node-6-2.new-localnet.com/10.20.40.36:

# mmchnode --daemon-interface=node-6-2.new-localnet.com -N node-6
Wed Sep 23 20:01:35 CEST 2020: mmchnode: Processing node node-6.localnet.com
Verifying GPFS is stopped on all nodes ...
Wed Sep 23 20:01:36 CEST 2020: mmchnode: Collecting ccr.nodes file version from all quorum nodes ...
Wed Sep 23 20:01:37 CEST 2020: mmchnode: Applying new change to ccr.nodes version 2 on all available quorum nodes ...
Wed Sep 23 20:01:40 CEST 2020: mmchnode: Committing new version of ccr.nodes file ...
mmchnode: Propagating the cluster configuration data to all affected nodes.
mmchnode: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

The mmlscluster command now shows the new daemon interface for node-6. Some lines of output are omitted:

# mmlscluster
GPFS cluster information
========================
...
 Node  Daemon node name           IP address      Admin node name      Designation
-----------------------------------------------------------------------------------
   1   node-6-2.new-localnet.com  10.20.40.36     node-6.localnet.com  quorum
   2   node-7.localnet.com        192.168.124.37  node-7.localnet.com  quorum
   3   node-8.localnet.com        192.168.124.38  node-8.localnet.com

The following example changes the daemon interface and the administration interface of multiple nodes:

The data file /tmp/specfile contains the following lines:

node-6 --daemon-interface=node-6-2.new-localnet.com --admin-interface=node-6-2.new-localnet.com
node-7 --daemon-interface=node-7-2.new-localnet.com --admin-interface=node-7-2.new-localnet.com
node-8 --daemon-interface=node-8-2.new-localnet.com --admin-interface=node-8-2.new-localnet.com

The mmchmode command changes the daemon interfaces and the administration interfaces of node-6, node-7, and node-8 based on the information in the data file:

mmchnode -S /tmp/specFile
Wed Sep 23 20:19:48 CEST 2020: mmchnode: Processing node node-6
Wed Sep 23 20:19:49 CEST 2020: mmchnode: Processing node node-7
Wed Sep 23 20:19:50 CEST 2020: mmchnode: Processing node node-8
Verifying GPFS is stopped on all nodes ...
Wed Sep 23 20:19:52 CEST 2020: mmchnode: Collecting ccr.nodes file version from all quorum nodes ...
Wed Sep 23 20:19:53 CEST 2020: mmchnode: Applying new change to ccr.nodes version 4 on all available quorum nodes ...
Wed Sep 23 20:19:56 CEST 2020: mmchnode: Committing new version of ccr.nodes file ...
mmchnode: Propagating the cluster configuration data to all affected nodes.
mmchnode: Propagating the cluster configuration data to all
  affected nodes.  This is an asynchronous process.

The mmlscluster command now shows the new daemon interfaces and administration interfaces for the three nodes. Some lines of output are omitted:

# mmlscluster
GPFS cluster information
========================
GPFS cluster name:         small_cluster.localnet.com
...
Node  Daemon node name             IP address      Admin node name               Designation
--------------------------------------------------------------------------------------
   1   node-6-2.new-localnet.com    10.20.40.36    node-6-2.new-localnet.com     quorum
   2   node-7-2.new-localnet.com    10.20.40.37    node-7-2.new-localnet.com     quorum
   3   node-8-2.new-localnet.com    10.20.40.38    node-8-2.new-localnet.com

To change node comments, issue the following command:

mmchnode -N k164n06  --comment="Bld 1. RM 205. Row 7c."

To view the comment information, issue the following command:

mmlscluster --comment

A sample output is as follows:

GPFS cluster information
========================
  GPFS cluster name:         c40bbc4xn10.gpfs.net
  GPFS cluster id:               126903473360907713
 Node  Daemon node name              Comment
--------------------------------------------
    1   k164n04.kgn.ibm.com
    2   k164n07.kgn.ibm.com
    3   k164n06.kgn.ibm.com           Bld 1. RM 205. Row 7c.

Location

/usr/lpp/mmfs/bin

mmchnode command

Synopsis

Availability

Description

Parameters

Exit status

Security

Examples

See also

Location