GPFS: Administration and Programming Reference - IRA Home

- The mmmount and mmumount commands are provided for cluster-wide file system
management, alleviating the need for the administrator to issue the dsh command.
- The mmlsmount command displays the IP addresses and names of the nodes (local and remote)
that have a particular file system mounted.
– Enhanced Network Shared Disk functions:
- An option to allow or restrict failover from local to remote access is now provided on the mmchfs,
mmmount, and mmremotefs commands.
In prior releases of GPFS, the only way to failback to local disk access once the connection had
been repaired and access through an NSD server was no longer desired, was to remount the file
system. In this release, GPFS discovers if the path has been repaired. If the path has been
repaired, GPFS falls back to local disk access.
- Improved NSD access information provided by the mmlsnsd command:
v The NSD identifier is now available when specifying the -L option.
v The device type of the disk is now available when specifying the -X option.
– Enhancements to the mmpmon performance monitoring tool:
- Use of a named socket. The mmpmon command no longer uses a network connection for
communication with the GPFS daemon.
- Extends support to include a list of nodes, in the local cluster, to report on instead of just the node
from which the command is issued.
- A new request, source, that specifies an input file for requests.
- A prefix request, once, that directs mmpmon to process a request only once.
– Enhanced mount support for clusters utilizing NSD servers.
You may now specify how long to wait for an NSD server to come online before allowing the mount
to fail. The mmchconfig command has been enhanced allowing to specify wait time when:
- Bringing a cluster online:
v The cluster formation time is at most nsdServerWaitTimeWindowOnMount seconds from the
current time.
v The number of seconds to wait for the server to come up before declaring the mount a failure
as specified by the nsdServerWaitTimeForMount option.
- Bringing an NSD server online when client nodes are already active:
v The last failed time is at most nsdServerWaitTimeWindowOnMount seconds from the current
time.
v The number of seconds to wait for the server to come up before declaring the mount a failure
as specified by the nsdServerWaitTimeForMount option.
– You may now specify different networks for GPFS daemon communication and for GPFS
administration command usage within your cluster. The node descriptor for the mmchcluster
command now allows you to specify separate node interfaces for these uses, for each node within
your cluster. You may choose to use this capability when considering cluster security or performance.
– Improved cluster network access. You may now specify the use of multiple networks for a node in
your cluster allowing both the use of internal networks within a cluster and the use of external
address for remote mounts. The mmchconfig command has been enhanced so that you may
specify a list of individual subnets used to communicate between nodes in a GPFS cluster, ordered
by preference (order in which operands are specified on the subnets option).
– GPFS now provides for the ability to distribute the token management function among multiple nodes
in a cluster, reducing possible bottlenecks. This feature is enabled by default. Nodes that have been
designated as manager nodes are used to distribute the token manager function.
See the General Parallel File System: Concepts, Planning, and Installation Guide for further
information on the roles of the file system manager and the General Parallel File System: Advanced
Administration Guide for details on distributed token managers.
– An autoconfiguration tool is now provided for GPFS for Linux installations.
xiv GPFS: Administration and Programming Reference