Platform LSF Reference Version 6.2

Platform LSF Reference
303
hosts
For hosts with multiple IP addresses and different official host names configured at the
system level, this file associates the host names and IP addresses in LSF.
By default, LSF assumes each host in the cluster:
◆ Has a unique “official” host name
◆ Can resolve its IP address from its name
◆ Can resolve its official name from its IP address
Hosts with only one IP address, or hosts with multiple IP addresses that already resolve
to a unique official host name should not be configured in this file: they are resolved
using the default method for your system (for example, local configuration files like
/etc/hosts or through DNS.)
The LSF
hosts file is used in environments where:
◆ Machines in cluster have multiple network interfaces and cannot be set up in the
system with a unique official host name
◆ DNS is slow or not configured properly
◆ Machines have special topology requirements; for example, in HPC systems where
it is desirable to map multiple actual hosts to a single “head end” host
The LSF
hosts file is not installed by default. It is usually located in the directory
specified by LSF_CONFDIR. The format of
LSF_CONFDIR/hosts is similar to the
format of the
/etc/hosts file on all UNIX machines.
hosts File Structure
One line for each IP address, consisting of the IP address, followed by the official host
name, optionally followed by host aliases, all separated by spaces or tabs. Each line has
the form:
ip_address official_name [alias [alias ...]]
Use consecutive lines for IP addresses belonging to the same host. You can assign
different aliases to different addresses.
Use a pound sign (#) to indicate a comment (the rest of the line is not read by LSF). Do
not use
#if as this is reserved syntax for time-based configuration.
A call to
gethostbyname(3N) returns a hostent structure containing the union of
all addresses and aliases from each line containing a matching official host name or alias.