NFS support overview
The NFS support for IBM Spectrum Scale™ enables clients to access the GPFS™ file system by using NFS clients with their inherent NFS semantics.
The following features are provided:
Clustered NFS Support
NFS clients can connect to any of the protocol nodes and get access to the exports defined. A clustered registry makes sure that all nodes see the same configuration data. This means that it does not matter to the client to which of the CES nodes the connections are established. Moreover, the state of opened files is also shared among the CES nodes so that data integrity is maintained. On failures, clients can reconnect to another cluster node as the IP addresses of failing nodes are automatically transferred to another healthy cluster node. The supported protocol levels are NFS version 3 (NFSv3) and NFS version 4 (NFSv4.0).
Export management commands
With the mmnfs export command, IBM Spectrum Scale provides a comprehensive entry point to manage all NFS-related export tasks such as creating, changing, and deleting NFS exports. The mmnfs export command follows the notions of supported options, that is, a limited set of NFS-related options that have proven useful. For more information, see the mmnfs command.
Export configuration commands
With the 
mmnfs config
command, IBM Spectrum Scale provides a tool for administering
the global NFS configuration. You can use this command to set and list default settings such as the
port number for the NFS service, the default access mode for exported file systems, and the NFS
server log level. This command follows the notions of supported options, that is, a limited set of
NFS-related options that have proven useful. For more
information, see the mmnfs command.
NFS monitoring
The monitoring framework detects issues with the NFS services and triggers failover in case of an unrecoverable error. Moreover, the mmces command provides a quick access to current and past system states and these states enable you to diagnose issues with the NFS services on the CES nodes. Issues that are detected and causing failover are, for example, GPFS daemon failures, node failures, or NFS service failures. For more information, see mmces command.
Integrated install
The integrated installer allows the installation of NFS services, CES framework, and the other protocols (SMB and Object), if desired.
NFS performance metrics
The NFS services provide performance metrics that are collected by the performance monitor framework. The mmperfmon query tool provides access to the most important NFS metrics through predefined queries. For more information, see the mmperfmon command.
Cross-protocol integration with SMB
IBM Spectrum Scale enables concurrent access to the same file data by using NFS, SMB, and native POSIX access (limitations apply). The first release does not allow the sharing of data through the traditional file protocols and Object.
Authentication and ID mapping
You can configure NFS services to authenticate against the most popular authentication services such as Microsoft Active Directory and LDAP. Mapping Microsoft security identifiers (SIDs) to the POSIX user and group IDs on the file server can either be done automatically or by using the external ID mapping service like RFC 2307. If none of the offered authentication and mapping schemes match the environmental requirements, the option to establish a user-defined configuration is available. The mmuserauth service create command can be used to set up all authentication-related settings. For more information, see the mmuserauth command.