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Conventions for naming nodes
© 2008, QNX Software Systems GmbH & Co. KG.
NFS was designed for filesystem operations between all hosts, all endians, and is
widely supported. It’s a connectionless protocol; the server can shut down and be
restarted, and the client resumes automatically. It also uses authentication and controls
directory access. For more information, see “NFS filesystem” in Working with
Filesystems.
Conventions for naming nodes
In order to resolve node names, the Qnet protocol follows certain conventions:
node name
A character string that identifies the node you’re talking to. This
name must be unique in the domain and can’t contain slashes or
periods.
The default node name is the value of the _CS_HOSTNAME
configuration string. If your hostname is localhost (the
default when you first boot), Qnet uses a hostname based on
your NIC hardware’s MAC address, so that nodes can still
communicate.
node domain
A character string that lsm-qnet.so adds to the end of the
node name. Together, the node name and node domain must
form a string that’s unique for all nodes that are talking to each
other. The default is the value of the _CS_DOMAIN
configuration string.
fully qualified node name (FQNN)
The string formed by concatenating the node name and node
domain. For example, if the node name is karl and the node
domain name is qnx.com, the resulting FQNN is
karl.qnx.com.
network directory
A directory in the pathname space implemented by
lsm-qnet.so. Each network directory — there can be more
than one on a node — has an associated node domain. The
default is /net, as used in the examples in this chapter.
The entries in /net for nodes in the same domain as your machine don’t include the
domain name. For example, if your machine is in the qnx.com domain, the entry for
karl is /net/karl; if you’re in a different domain, the entry is
/net/karl.qnx.com.
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name resolution
The process by which lsm-qnet.so converts an FQNN to a
list of destination addresses that the transport layer knows how
to get to.
name resolver
A piece of code that implements one method of converting an
FQNN to a list of destination addresses. Each network directory
Chapter 12 • Using Qnet for Transparent Distributed Processing
September 30, 2008