LSF Version 7.3 - Administering Platform LSF

Hosts with Multiple Addresses
88 Administering Platform LSF
Hosts with Multiple Addresses
Multi-homed hosts
Hosts that have more than one network interface usually have one Internet address
for each interface. Such hosts are called multi-homed hosts. For example, dual-stack
hosts are multi-homed because they have both an IPv4 and an IPv6 network
address.
LSF identifies hosts by name, so it needs to match each of these addresses with a
single host name. To do this, the host name information must be configured so that
all of the Internet addresses for a host resolve to the same name.
There are two ways to do it:
◆ Modify the system hosts file (/etc/hosts) and the changes will affect the
whole system
◆ Create an LSF hosts file (LSF_CONFDIR/hosts) and LSF will be the only
application that resolves the addresses to the same host
Multiple network interfaces
Some system manufacturers recommend that each network interface, and
therefore, each Internet address, be assigned a different host name. Each interface
can then be directly accessed by name. This setup is often used to make sure NFS
requests go to the nearest network interface on the file server, rather than going
through a router to some other interface. Configuring this way can confuse LSF,
because there is no way to determine that the two different names (or addresses)
mean the same host. LSF provides a workaround for this problem.
All host naming systems can be configured so that host address lookups always
return the same name, while still allowing access to network interfaces by different
names. Each host has an official name and a number of aliases, which are other
names for the same host. By configuring all interfaces with the same official name
but different aliases, you can refer to each interface by a different alias name while
still providing a single official name for the host.
Configuring the LSF hosts file
If your LSF clusters include hosts that have more than one interface and are
configured with more than one official host name, you must either modify the host
name configuration, or create a private
hosts file for LSF to use.
The LSF
hosts file is stored in LSF_CONFDIR. The format of LSF_CONFDIR/hosts
is the same as for
/etc/hosts.
In the LSF
hosts file, duplicate the system hosts database information, except
make all entries for the host use the same official name. Configure all the other
names for the host as aliases so that you can still refer to the host by any name.
Example For example, if your /etc/hosts file contains:
AA.AA.AA.AA host-AA host # first interface
BB.BB.BB.BB host-BB # second interface
then the LSF_CONFDIR/hosts file should contain:
AA.AA.AA.AA host host-AA # first interface