mmnfs command

Availability

Available on all IBM Spectrum Scale editions.

Description

Use the mmnfs export commands to add, change, list, load, or remove NFS export declarations for IP addresses on nodes that are configured as CES types.

Use the mmnfs config commands to list and change NFS configuration.

The protocol functions provided in this command, or any similar command, are generally referred to as CES (Cluster Export Services). For example, protocol node and CES node are functionally equivalent terms.

Parameters

export

Manages the NFS export configuration for the cluster with one of the following actions:

add

Creates a new configuration file for the NFS server in case it does not yet exist. If there is already an export configuration file, then it is extended with the provided additional export parameters. This export configuration file is used by the NFS server to create an NFS export for the Path so that clients can connect to it. If there is already an existing export for the Path then an error is shown. Each export configuration set has internally its own unique identifier number. This number is automatically incremented for each added export. The mmnfs export add command attempts to add the new export also to running NFS server instances, and may fail if one or more instances are not running. This is not a critical issue, since the configuration changes have been made in the repository and will be applied later when restarting the NFS server instance.

The authentication method must be established before an NFS export can be defined.

The export Path must be an existing path in the GPFS file system.

Note: The paths which are not within the GPFS file system cannot be exported using the commands.

Creating nested exports (such as /path/to/folder and /path/to/folder/subfolder) is not recommended as this might lead to serious issues in data consistency. Remove the higher-level export that prevents the NFSv4 client from descending through the NFSv4 virtual filesystem path. In case nested exports cannot be avoided, ensure that the export with the common path, called as the top-level export, has all the permissions for this NFSv4 client. Also NFSv4 client that mounts the parent (/path/to/folder) export does not see the child export subtree (/path/to/folder/inside/subfolder) unless the same client is explicitly allowed to access the child export as well.

--client {ClientOption[;ClientOption...]}

Declares the client specific settings. You can specify a list of one or more client definitions. To avoid incorrect parsing by the interpreter, quote the argument list. For a list of client definitions that can be specified with the --client option, see List of supported client options for the mmnfs export {add | change} command.

Some export configuration commands might allow multiple client declarations, and therefore they have separators to distinguish them.

The following separators can be used:

• Colon to separate multiple allowed values for a specified attribute. For example, the key/value pair "Protocols=3:4" allows the NFS protocols v3 and v4 to be declared for an export.
• Comma to separate key/value pairs within a client declaration list and a Semicolon to separate client declaration lists.

  For example:

  --client "192.0.2.0/20(Access_Type=RW,Protocols=3:4); \
  198.51.100.0/20(Access_Type=RO,Protocols=3:4,Transports=TCP:UDP)"

Note: To take advantage of the GPFS independent fileset features such as quotas, snapshots, and data management, the export paths can be made from GPFS filesets (either dependent or independent).

--pseudo

Specifies the path name the NFSv4 client uses to locate the directory in the server's file system tree.

Note: This option is applicable to NFSv4 mounts only.

remove

Removes the requested export from the configuration file and also from running NFS server instances, and might fail if one or more instances are not running.

Note: This command does not remove data.

The --force option is not used.

change

Modifies an existing export configuration for the export that is specified by Path, if the export exists. If the export does not exist, then an error is shown.

Note: Only client-related attributes are modified by this command, but not the basic export settings such as path.

The --nfsposition flag can be only used together with either --nfsadd or --nfschange. It cannot be used standalone or together with --nfsremove. When --nfsadd and --nfsremove are given on the same command line, then the remove procedure is executed first internally.

--nfsadd {ClientOption[;ClientOption...]}

Adds a new client declaration for the specified Path. You can list one or more client definitions. To avoid incorrect parsing by the interpreter, quote the argument list. For a list of client definitions that can be specified with the --client option, see List of supported client options for the mmnfs export {add | change} command.

--nfsremove {Client[,Client...]}

Removes the NFS client specified by Client from the export configuration for the Path. Client can be a single client specifier, or a comma-separated list of client specifiers. If a client is the only one within a client declaration section in the configuration file, then this client section is removed.

Note: When the last client within a client declaration is removed, then the export section is also removed.

--nfschange {ClientOption[;ClientOption...]}

Modifies an existing client declaration for the specified Path. You can specify a list of one or more client definitions. To avoid incorrect parsing by the interpreter, quote the argument list. For a list of client definitions that can be specified with the --client option, see List of supported client options for the mmnfs export {add | change} command. If a client specifier declared in ClientOption matches a client declaration section, which has further NFS clients that are assigned, then this section is split into a section containing that client specifier together with the modified attributes, and a section with the remaining client specifiers and their original attributes.

The --nfsposition option can be used to locate this modified entry.

--nfsposition {PositionIndex | Client}

This option can be used only together with --nfsadd or --nfschange. It reorders the client declaration section within the export declaration file. The sequence of client entries can be important when there are different client sections affecting the same NFS client. For example, NFS position can be important when defining export attributes for a specific NFS client, and '*' for all NFS clients, given the same export path.

PositionIndex

This must be an unsigned numeric value, and it indicates the absolute sequence number after reordering the client declarations. The indexing is zero-based. 0 means the top of the list, 1 means the second entry, and so on. Any number higher than the number of existing entries indicates the end-of-list position.

Client

The reference client specifier to indicate the new position of the current client entry. The modified client entry is placed at the location where the Client reference declaration is, and that section is ordered below next to the modified client section.

list

Lists the declared exports and clients. The sequence of rows in the output for a given path reflects also the sequence of the internal client declaration list for each exported path. The sequence of client declarations within an export can be reordered using the mmnfs export change Path with the --nfschange and --nfsposition options. The output can be formatted human readable (default) or machine readable.

--nfsdefs Path

Lists the export configuration details for the specified Path.

-Y

Displays the command output in a parseable format with a colon (:) as a field delimiter. Each column is described by a header.

Note: Fields that have a colon (:) are encoded to prevent confusion. For the set of characters that might be encoded, see the command documentation of mmclidecode. Use the mmclidecode command to decode the field.

--nfsdefs-match Path

Lists the export configuration details of all export paths, which contain the specified string.

load

Overwrites (deletes) all existing NFS export declarations in the repository, if any. The export declarations are fetched from a file provided to the load operation, which could contain a larger number of export declarations. Some basic format checks are done during export load. After loading export declarations from a file, the NFS service is restarted across all the nodes in the cluster.

ExportCFGFile

The file name for the new exports declarations. This file is loaded and stored in the repository to be published on all CES nodes running the NFS server. This load procedure can be used to load a set of export declarations and that removes any previous configuration. The NFS servers are restarted in order to apply the changes.

List of supported client options for the mmnfs export {add | change} command:

ACCESS_TYPE

Allowed values are none, RW, RO, MDONLY, and MDONLY_RO. The default value is none.

PROTOCOLS

Allowed values are 3, 4, NFS3, NFS4, V3, V4, NFSv3 , and NFSv4. The default value is 3,4.

TRANSPORTS

Allowed values are TCP and UDP. The default value is TCP.

ANONYMOUS_UID

Allowed values are between -2147483648 and 4294967295. The default value is -2.

ANONYMOUS_GID

Allowed values are between -2147483648 and 4294967295. The default value is -2.

SECTYPE

Allowed values are none, sys, krb5, krb5i, and krb5p. The default value is sys.

PRIVILEGEDPORT

Allowed values are true and false. The default value is false.

MANAGE_GIDS=true

In this configuration, NFS server discards the list of GIDs passed via the RPC and fetch the group information. For getting the group list, the server makes use of the default authentication configured on the system (CES node). So, depending on the configuration, the list is obtained by using (/etc/passwd + /etc/groups) or from LDAP or from AD. To reach AD and get the list of GIDs, the client must use sec=krb5, else NFS server is not able to get the list from AD.

MANAGE_GIDS=false

NFS server makes use of list of GIDs passed by RPC.

SQUASH

Allowed values are root, root_squash, all, all_squash, allsquash, no_root_squash, none , and noidsquash. The default value is root_squash.

NFS_COMMIT

Allowed values are true and false. The default value is false.

Important: Use NFS_COMMIT very carefully because it changes the behavior of how transmitted data is committed on the server side to a NFS v2 like sync-mode on every write action.

CLIENTS

Allowed values are IP addresses in IPv4 or IPv6 notations, hostnames, netgroups, or * for all. A netgroup name must not start with a numeric character and otherwise must only contain underscore and/or hyphens ("[a-zA-Z_][0-9a-zA-Z_\- .]*"). The default value is *.

config

Manages NFS configuration for a CES cluster:

list

Displays the NFS configuration parameters and their values. This command also displays all the default export configurations. This is used as the defaults by the mmnfs export add command if no other client attributes are specified. The output can be formatted to be human readable or machine readable.

--exportdefs

If this option is specified, the command displays the default export configuration parameters.

-Y

Displays the command output in a parseable format with a colon (:) as a field delimiter. Each column is described by a header.

Note: Fields that have a colon (:) are encoded to prevent confusion. For the set of characters that might be encoded, see the command documentation of mmclidecode. Use the mmclidecode command to decode the field.

change

Modifies the NFS configuration parameters. NFS is restarted across all the nodes on which NFS is running, when this command is executed. Only some configuration options can be modified by this command.

The configuration options that can be modified and their allowed values are as follows:

NFS_PROTOCOLS

Allowed values are 3, 4, NFS3, NFS4, V3, V4, NFSv3 , and NFSv4. The default value is 3,4.

MNT_PORT

Specifies the port for the NFSv3 Mount protocol. Allowed values are between 0 and 65535. The default value is 0.

NLM_PORT

Specifies the NLM port for NFSv3. Allowed values are between 0 and 65535. The default value is 0.

RQUOTA_PORT

Specifies the RQUOTA port for NFSv3. Allowed values are between 0 and 65535. The default value is 0.

STATD_PORT

Specifies the STATD port for NFSv3. Allowed values are between 0 and 65535. The default value is 0.

LEASE_LIFETIME

Specifies the value in seconds during which an NFS server requires an NFS client to do some operation to renew its lease. This is specific to NFSV4. Allowed values are between 0 and 120. The default value is 60.

GRACE_PERIOD

Specifies the time in seconds during which an NFS client is required to reclaim its locks, in the case of NFSv3, and additionally its state, in the case of NFSv4. Allowed values are between 0 and 180. The default is 60.

DOMAINNAME

String. The default value is the "host's fully-qualified DNS domain name".

IDMAPD_DOMAIN

String. Domain in the ID Mapd configuration. The default value is the host's fully-qualified DNS domain name.

LOCAL_REALMS

String. Local-Realms in the ID Mapd configuration. The default value is the host's default realm name.

LOG_LEVEL

Allowed values are NULL, FATAL, MAJ, CRIT, WARN, EVENT, INFO , DEBUG, MID_DEBUG, and FULL_DEBUG. The default value is EVENT.

ENTRIES_HWMARK

The high water mark for NFS cache entries. Beyond this point, NFS tries to evict some objects from its cache. The default is 1500000.

Note: Specifying a port number in the NFS service configuration with the value of '0' means that the service is picking a port number dynamically. This port number might change across service restarts. If a firewall is to be established between the NFS server and the NFS clients, specific port number can be configured via the command to establish discrete firewall rules. Note that the NFS_PORT 2049 is a well-known and established convention as NFS servers and clients typically expect this port number. Changing the NFS service port numbers impacts existing clients and a remount of the client is required.

The export defaults that can be set are:

ACCESS_TYPE

Allowed values are none, RW, RO, MDONLY, and MDONLY_RO. The default value is none.

Note: Changing this option to any value other than none exposes data to all NFS clients that can access your network, even if the export is created using add --client ClientOptions to limit that clients access. All clients, even if not declared with the --client in the mmnfs export add, has access to the data. The global value applies to an unseen *, even if showmount -eCESIP does not display it. Use caution if you change it in this global definition.

ANONYMOUS_UID

Allowed values are between -2147483648 and 4294967295. The default value is -2.

ANONYMOUS_GID

Allowed values are between -2147483648 and 4294967295. The default value is -2.

MANAGE_GIDS

Allowed values are true and false. The default value is false.

NFS_COMMIT

Allowed values are true and false. The default value is false.

Important: Use NFS_COMMIT very carefully because it changes the behavior of how transmitted data is committed on the server side to a NFS v2 like sync-mode on every write action.

PRIVILEGEDPORT

Allowed values are true and false. The default value is false.

PROTOCOLS

Allowed values are 3, 4, NFS3, NFS4, V3, V4, NFSv3 , and NFSv4. The default value is 3,4.

SECTYPE

Allowed values are none, sys, krb5, krb5i, and krb5p. The default value is sys.

SQUASH

Allowed values are root, root_squash, all, all_squash, allsquash, no_root_squash, none , and noidsquash. The default value is root_squash.

Note: Changing this option to no_root_squash exposes data to root on all NFS clients, even if the export is created using add --client ClientOptions to limit the root access of that client.

TRANSPORTS

Allowed values are TCP and UDP. The default value is TCP.

If export defaults are set, then new exports that are created pick up the export default values. If an export configuration value is not specified, the current export default value is used.

Note: For exports created before IBM Spectrum Scale 5.0.2, the export default value at the time of its creation is used.

Exit status

0

Successful completion.

nonzero

A failure has occurred.

Security

You must have root authority to run the mmnfs command.

The node on which the command is issued must be able to execute remote shell commands on any other CES 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.

See also

Location