IBM Books

IBM General Parallel File System for AIX: Administration and Programming Reference

mmconfig Command

Name

mmconfig - Defines a new GPFS nodeset and configures GPFS prior to creating file systems.

Synopsis

mmconfig {-a | -n NodeFile } [-A] [-C NodesetId] [-D dataStructureDump] [-M maxFilesToCache] [-p pagepool] [-U{yes | no}] [-V {yes | no}]

Description

The mmconfig command defines a new GPFS nodeset and configures GPFS prior to creating file systems. Before creating a GPFS nodeset, all of the nodes that are to be included in the nodeset must be part of the GPFS cluster. For further information see the mmcrcluster Command and the mmaddcluster Command.

Results

Upon successful completion of the mmconfig command these tasks are performed on all specified nodes:

Parameters

-a
Adds all nodes to the new nodeset. In an SP environment, this is all of the nodes in the SDR. In an HACMP environment, this is all of the nodes in the GPFS cluster. This designation is not valid if there are existing nodesets.

-n Nodefile
NodeFile consists of a list of nodes, one per line, to be included in the new nodeset and each is specified in the form NodeName[:manager | client]

The hostname or IP address used for a node must refer to the adapter port over which the GPFS daemons communicate. Alias interfaces are not allowed. Use the original address or a name that is resolved by the host command to that original address. You may specify a node using any of these forms:
Format Example
Short hostname k145n01
Long hostname k145n01.kgn.ibm.com
IP address 9.119.19.102

NodeName may be optionally followed by a use designation. All nodes in the nodeset may not be designated as client nodes. The designation specifies whether or not the node should be included in the pool of nodes from which the File System Manager node is chosen. For further information on the roles of nodes as File System Managers, see the IBM General Parallel File System for AIX: Concepts, Planning, and Installation Guide and search for File System Manager. The default is to have the node included in the pool.

Options

-A
Specifies that GPFS daemons are to be automatically started when nodes come up. The default is not to start daemons automatically.

-C NodesetId
The identifier for the new nodeset. It can be at most eight alphanumeric characters long. It may not be any reserved words (such as AVAIL or VSD) or the number zero.

If you do not provide an identifier, the system assigns one. The system assigns each nodeset an integer identifier, beginning with one and increasing sequentially.

-D dataStructureDump
Specifies a path for the storage of dumps. The default is to store dumps in /tmp/mmfs. Specify no to store no dumps.

It is suggested that you create a directory for the placement of certain problem determination information. This can be a symbolic link to another location if more space can be found there. It should not be placed in a GPFS file system as it might not be available should GPFS fail. If a problem should occur, GPFS may write 200MB or more of problem determination data into the directory. These files must be manually removed when any problem determination is complete. This should be done promptly so that a NOSPACE condition is not encountered during the next failure.

-M maxFilesToCache
Specifies the number of inodes to cache for recently used files that have been closed. Storing a file's inode in cache permits faster reaccess to the file. The default is 1000 but increasing this number may improve throughput for workloads with high file reuse. However, increasing this number excessively may cause paging at the File System Manager node.

-p pagepool
Specifies the size of the cache on each node. It can range from a minimum of 4M to a maximum of 512M per node. This value should be specified with the character M. The default is 20M.

-U {yes | no}
In a two-node nodeset, specifies whether or not to allow single-node quorum to be in effect and start the daemon if only one node is available (see the IBM General Parallel File System for AIX: Concepts, Planning, and Installation Guide and search for quorum). This flag is ignored if more than two nodes have been defined to the GPFS nodeset. Valid values are yes or no. The default is not to allow two-node nodesets.
Note:
When using Fibre Channel disks, single-node quorum is not supported.

Exit status

0
Successful completion.

1
A failure has occurred and an error message is printed to stdout.

If a node is down or is not a member of the GPFS cluster, the mmconfig command fails. If the node is not a member of the GPFS cluster, you must:

  1. Issue the mmcrcluster command if it had not been run.
  2. Issue the mmaddcluster command if a GPFS cluster has already been defined.
  3. Re-issue the mmconfig command.

Security

You must have root authority to run the mmconfig command.

In an SP environment:

  1. Verify the authentication method set for SP security services:
    1. If your authentication method is set to compatibility, Kerberos authentication is required. Issue the k4init command.
    2. If your authentication method is set to DCE, dce_login authentication is required.
    3. If your authentication method is set to NONE/std, there must be an entry in the /etc/sysctl.mmcmd.acl file on every node in the nodeset for the root user at every other node in the nodeset.

    For further information, see the latest IBM Parallel System Support Programs for AIX: Administration Guide, IBM Parallel System Support Programs for AIX: Command and Technical Reference, and RS/6000: Planning Volume 2, Control Workstation and Software Environment manuals at www.rs6000.ibm.com/resource/aix_resource/sp_books/pssp. Search for information on sysctl.

  2. You may issue the mmconfig command from any node running GPFS or the CWS.
  3. If you are executing mmconfig from the CWS on a multi-partitioned system, the SP_NAME environment variable must be properly set. It is suggested that you use a separate window for each partition and set the environment variable accordingly. For further information, see the IBM Parallel System Support Programs for AIX: Administration Guide and search for understanding system partitioning.

In an HACMP environment:

  1. When using rcp and rsh for remote communication, a properly configured /.rhosts file must exist in the root user's home directory on each node in the GPFS cluster. If you have designated the use of a different remote communication program on either the mmcrcluster or the mmchcluster command, you must insure:
    1. Proper authorization is granted to all nodes in the GPFS cluster.
    2. The nodes in the GPFS cluster can communicate without the use of a password.
  2. You may issue the mmconfig command from any node in the GPFS cluster.

Examples

To configure all of the nodes listed in the file, system_1, for the new nodeset, set1, and have GPFS automatically started when the nodes come up, enter:

mmconfig -n /gpfsAdmin/system_1 -A -C set1

To confirm what the GPFS configuration is, enter:

mmlsconfig set1

The system displays information similar to:

Configuration data for nodeset set1:  
-----------------------------------  
pagepool 20M                        
dataStructureDump /log/mmfs          
multinode yes                        
autoload yes                          
useSingleNodeQuorum no               
wait4RVSD no                         
comm_protocol TCP                   
clusterType sp                       
group Gpfs.set1                       
recgroup GpfsRec.set1                 
useDiskLease no                      
                                     
File systems in nodeset set1:         
----------------------------         
(none)                         
 

See also

mmaddcluster Command

mmaddnode Command

mmchcluster Command

mmchconfig Command

mmcrcluster Command

mmdelcluster Command

mmdelnode Command

mmlscluster Command

mmlsconfig Command

mmlsnode Command

Location

/usr/lpp/mmfs/bin


[ Top of Page | Previous Page | Next Page | Table of Contents | Index ]