mmvdisk server command

Manages mmvdisk recovery group servers for IBM Spectrum Scale RAID.

Synopsis

mmvdisk server configure {--node-class NcName | -N Node[,Node...]}  
                         [--recycle {none|one|all|Number}]
                         [--pagepool{nM | nG | nT | n%}]
                         [--maxblocksize {2M | 4M | 8M | 16M}]

mmvdisk server unconfigure {--node-class NcName | -N Node[,Node...]}
                           [--recycle {none | one | all | Number}]

mmvdisk server list [-Y]

mmvdisk server list {--node-class NcName |-N Node[,Node...] | --recovery-group RgName} 
                    [--version] [--config] [--disk-topology [--fanout N]] [-Y]

mmvdisk server list -N Node --disk-topology -L  [-Y]

Availability

Available on all IBM Spectrum Scale editions.

Description

Use the mmvdisk server command to manage mmvdisk recovery group servers.

Before an IBM Spectrum Scale RAID recovery group can be created, the mmvdisk node class for the intended recovery group Start of change or recovery group pair End of change must be configured to run IBM Spectrum Scale RAID and the IBM Spectrum Scale daemon must be restarted on each server in the node class. The mmvdisk server configure command examines the nodes in an mmvdisk node class, verifies that the node class members meet the same memory and disk topology requirements, and sets the appropriate configuration parameters. End of change The mmvdisk server configure command can be used to optionally recycle the IBM Spectrum Scale daemon on the node class to ensure that the new configuration is in effect.

Start of change The configuration parameters set by mmvdisk server configure depend on the amount of server memory and the type of server disk topology. All node class members must have, within ten percent, the same amount of memory, and all node class members must have either a paired recovery group (Elastic Storage Server) disk topology or a scale-out recovery group (IBM Spectrum™ Scale Erasure Code Edition) disk topology. The mmvdisk server configure command will not configure a node class where the server memory differs by more than ten percent or where a mixture of scale-out and paired recovery group topologies are present. End of change

Start of change The mmvdisk server configure command can be used to optionally recycle the IBM Spectrum Scale daemon on the recovery group server node class to ensure that the new configuration is in effect for a subsequent mmvdisk recoverygroup create command. End of change

The mmvdisk server configure command can also be used to configure individual nodes for IBM Spectrum Scale RAID to prepare for maintenance use cases where servers are replaced or added to a recovery group and its node class.

The mmvdisk server unconfigure command will remove IBM Spectrum Scale RAID configuration from a node class where a recovery group was either deleted or never created. The mmvdisk server unconfigure command can also be used to unconfigure IBM Spectrum Scale RAID on individual nodes for maintenance use cases where servers are replaced or deleted from a recovery group and its node class.

The mmvdisk server list command, without any options, will list all the configured IBM Spectrum Scale RAID servers in the cluster. It identifies all recovery group servers and all nodes configured to be recovery group servers, regardless of whether the servers are members of an mmvdisk node class. This can be useful for planning server maintenance and planning the conversion of recovery groups and servers to mmvdisk management.

The mmvdisk server list command supports several options useful for showing server characteristics. The --node-class option will show whether the servers in a node class are active and the recovery group they serve. The --version option can be used to show the IBM Spectrum Scale and operating system versions for servers. The --config option can be used to show important aspects of the IBM Spectrum Scale RAID server configuration.

The mmvdisk server list --disk-topology option is important for reporting the supported IBM Spectrum Scale RAID disk topology on a node class or server. Start of change It should be used before mmvdisk server configure on a node class, to verify that all the node class members have the same server disk topology. End of change It can also be used to help identify disk configuration problems that prevent nodes from acting as recovery group servers.

Parameters

mmvdisk server configure: Configure nodes or an mmvdisk node class to be IBM Spectrum Scale RAID servers. The nodes or node class must not already be serving a recovery group or already be configured.
mmvdisk server unconfigure: Unconfigure nodes or an mmvdisk node class to no longer be IBM Spectrum Scale RAID servers. The nodes or node class must no longer be associated with a recovery group.
mmvdisk server list: List IBM Spectrum Scale RAID servers and their characteristics.A node is considered to be a server if it is in the server list of a recovery group, or if it is member of an mmvdisk node class, or if it has the IBM Spectrum Scale RAID nsdRAIDTracks attribute set.
--node-class NcName: Specifies a single mmvdisk node class name to be configured, unconfigured, or listed.
-N Node[,Node...]: Specifies individual nodes to be configured, unconfigured, or listed
--recycle {none | one | all | Number}: With mmvdisk server configure or mmvdisk server unconfigure, specifies the number of nodes to be simultaneously restarted so that IBM Spectrum Scale configuration changes can take effect. The default is none, meaning that the administrator is responsible for using the mmshutdown and mmstartup commands to recycle the nodes or node class. The keyword one will recycle one node at a time, the keyword all will recycle all specified nodes simultaneously, or a Number of nodes can be chosen to be recycled at the same time. Care should be taken when recycling nodes if it is desired to maintain quorum availability in the IBM Spectrum Scale cluster.
--pagepool {nM | nG | nT | n%}: With mmvdisk server configure, choose a specific IBM Spectrum Scale pagepool value. Normally, mmvdisk server configure chooses the best appropriate pagepool size for the real memory available in the server node class, so this option should only be used under instruction from IBM®.
--maxblocksize {2M | 4M | 8M | 16M}: With mmvdisk server configure, also set the IBM Spectrum Scale cluster maxblocksize value. Even though maxblocksize is not a server-specific configuration value, IBM Spectrum Scale RAID is often used with large file system block sizes, and this option provides a convenient way to set the maximum file system block size. This would typically be done only when configuring the first recovery group in a cluster, and it requires that the administrator ensure that the IBM Spectrum Scale daemon on all cluster nodes is recycled (not only on the recovery group server nodes).
--recovery-group RgName: With mmvdisk server list, lists the servers for the named recovery group.
--version: With mmvdisk server list, lists the IBM Spectrum Scale and operating system version for the servers.
--config: With mmvdisk server list, lists the IBM Spectrum Scale RAID configuration for the servers.
--disk-topology: With mmvdisk server list, lists the discovered IBM Spectrum Scale RAID disk topology on the servers.
--fanout N: With mmvdisk server list --disk-topology, chooses how many servers to query simultaneously for their disk topologies. The default is 32. A fanout of 1 can be useful when disk fabric errors with twin-tailed server pairs are suspected.
-L: With mmvdisk server list --disk-topology and a single node, provide a detailed listing of the discovered IBM Spectrum Scale RAID disk topology. This is very useful when disk topology errors are suspected.
-Y: Specifies that the mmvdisk server list command produce colon-delimited raw output.

Exit status

0: Successful completion.
nonzero: A failure has occurred.

Security

You must have root authority to run the mmvdisk server command.

The node on which the command is issued must be able to execute remote shell commands on any other node in the cluster without the use of a password and without producing any extraneous messages.

Example

To display the IBM Spectrum Scale RAID disk topology of the servers in mmvdisk node class, ESS01:

mmvdisk server list --node-class ESS01 --disk-topology

The system displays output similar to the following:

 node                                       needs    matching
number  server                            attention   metric   disk topology
------  --------------------------------  ---------  --------  -------------
     1  server01.gpfs.net                 no          100/100  ESS GL6
     2  server02.gpfs.net                 no          100/100  ESS GL6

Example

To configure mmvdisk node class ESS01 to be IBM Spectrum Scale RAID recovery group servers and restart the daemons one at a time to make the configuration take effect:

mmvdisk server configure --node-class ESS01 --recycle one

The system displays output similar to the following:

mmvdisk: Checking resources for specified nodes.
mmvdisk: Node 'server01.gpfs.net' has a paired recovery group disk topology.
mmvdisk: Node 'server02.gpfs.net' has a paired recovery group disk topology.
mmvdisk: Node class 'ESS01' has a paired recovery group disk topology.
mmvdisk: Setting configuration for node class 'ESS01'.
mmvdisk: Node class 'ESS01' is now configured to be recovery group servers.
mmvdisk: Restarting GPFS on the following nodes:
mmvdisk:     server01.gpfs.net
mmvdisk: Restarting GPFS on the following nodes:
mmvdisk:     server02.gpfs.net

Example

To show the status of the newly-configured mmvdisk node class ESS01:

mmvdisk server list --node-class ESS01

The system displays output similar to the following:

 node
number  server                            active   remarks
------  --------------------------------  -------  -------
     1  server01.gpfs.net                 yes      configured, idle
     2  server02.gpfs.net                 yes      configured, idle

This shows that the servers are configured and running, but IBM Spectrum Scale RAID is idle because recovery groups have not yet been created.

Example

To display the disk topology of the scale-out recovery group servers of recovery group RG01:

mmvdisk server list --recovery-group RG01 --disk-topology

The system displays output similar to the following:

 node                                       needs    matching
number  server                            attention   metric   disk topology
------  --------------------------------  ---------  --------  -------------
     1  s01                               no          100/100  ECE 2 SSD/NVMe and 5 HDD
     2  s02                               no          100/100  ECE 2 SSD/NVMe and 5 HDD
     3  s03                               no          100/100  ECE 2 SSD/NVMe and 5 HDD
     4  s04                               no          100/100  ECE 2 SSD/NVMe and 5 HDD
     5  s05                               no          100/100  ECE 2 SSD/NVMe and 5 HDD

Example

To display the current status of the servers of recovery group RG01:

mmvdisk server list --recovery-group RG01

The system displays output similar to the following:

 node
number  server                            active   remarks
------  --------------------------------  -------  -------
     1  s01                               yes      serving RG01: LG003, LG008
     2  s02                               yes      serving RG01: root, LG005, LG010
     3  s03                               yes      serving RG01: LG002, LG007
     4  s04                               yes      serving RG01: LG001, LG006
     5  s05                               yes      serving RG01: LG004, LG009

Location

/usr/lpp/mmfs/bin

mmvdisk server command

Synopsis

Availability

Description

Parameters

Exit status

Security

Example

Example

Example

Example

Example

See also

Location