GPFS port usage
The nodes in a GPFS™ cluster communicate with each other using the TCP/IP protocol. The port number used by the main GPFS daemon (mmfsd) is controlled with the tscTcpPort configuration parameter. The default port number is 1191.
mmchconfig tscTcpPort=PortNumber
mmchconfig mmsdrservPort=PortNumber
Do
not change the mmsdrserv port number to a number different
from that of the daemon port number.mmchconfig tscCmdPortRange=LowNumber-HighNumber
mmremotecluster update ClusterName -n tcpPort=PortNumber,Node,Node...
Table 1 provides GPFS port usage information:
Descriptor | Explanation |
---|---|
Service provider | GPFS |
Service name | mmfsd |
Port number | 1191 While executing certain commands, GPFS may need to create additional sockets whose dynamic port numbers are assigned by the operating system. Such sockets are used by commands to exchange data with GPFS daemons running on other nodes. The port numbers that are used correspond to the ephemeral ports of the operating system. To control which ports are used by the commands (so that firewall rules can be written to allow incoming traffic only on those ports), you can restrict the port range to a specific range by setting the tscCmdPortRange configuration variable. |
Protocols | TCP/IP |
Source port range | The source port range is chosen by the operating system on the client side. |
Is the service name/number pair in the default /etc/services file shipped with AIX® and Linux distributions? | See the IBM Spectrum Scale™ FAQ in IBM® Knowledge Center. |
Is the service name/number pair added to /etc/services by a product? | No |
Binaries that listen on the ports | /usr/lpp/mmfs/bin/mmfsd |
Can the service be configured to use a different port? | Yes. To change the main port used by GPFS, use:
Note: If
you change the main port (daemon port) number, you must change the mmsdrserv port
to the same number.
To change the mmsdrserv port number
to match the daemon port number, use:
To change the range of port numbers used for command execution,
use:
To specify a port number when connecting to remote clusters, use the mmremotecluster command. |
When is the service required? What depends on the service? | On the GPFS primary and secondary cluster configuration servers, either mmsdrserv or mmfsd needs to be running at all times to provide access to GPFS configuration data to the rest of the cluster. On other nodes, mmfsd must be running in order to mount a GPFS file system. Depending on the GPFS configuration, a node either has to be a member of the GPFS cluster or possess an authorized SSL key in order to establish a connection. |
When the daemon starts and its port is already in use (for example, another resource has bound to it already), how does the daemon behave? | The daemon shuts down and tries to start over
again. Most GPFS daemon down error messages are in the mmfs.log.previous log for the instance that failed. If the daemon restarted, it generates a new mmfs.log.latest log. Begin problem determination for these errors by examining the operating system error log. GPFS records file system or disk failures using the error logging facility provided by the operating system: syslog facility on Linux and errpt facility on AIX. See the IBM Spectrum Scale: Problem Determination Guide for further information. |
Is there an administrator interface to query the daemon and have it report its port number? | Yes; run this command:
|
Is the service/port registered with the Internet Assigned Numbers Authority (IANA)? | Yes
|