Reference

mosix.map(5)

Mosix cluster configuration file

NAME

mosix.map – Mosix cluster configuration file

DESCRIPTION

The file /etc/mosix.map defines the computer-nodes in the MOSIX cluster by mapping MOSIX node-numbers to IP addresses. Each Line (other than blank or comment-lines beginning with a #) usually describes a range of nodes with consecutive IPs. Each line contains 3 fields:

MOSIX-node-number

of the first node in the range (any small integer up to 65535).

IP-address -

of the first node in the range, or its corresponding host-name as listed in "/etc/hosts".

range-size -

the number of nodes in the range.

If, however, this range-size is either 0 or the word "ALIAS", the line describes an alternative IP address for the given MOSIX node (this is necessary when that MOSIX node has more than one IP address because it also acts as a gateway between two or more networks of MOSIX nodes in the same cluster).

The maximum number of lines, i.e. ranges or aliases, is MAX_MOSNET_ENTS as defined in include/linux/mosctl.h (currently 256).

IMPORTANT NOTES

  1. The /etc/mosix.map file is expected to be identical on all nodes in the cluster.

  2. The common complaint: "The table is ok, but I'm not there!" means that the IP of the local node is not included in the table. The local IP is used in conjunction with /etc/mosix.map to determine the local node number.

    The IP of the local node is usualy found using the combination of gethostname(2) and gethostbyname(3): if, for any reason, the resulting IP is not listed in /etc/mosix.map, then the local node number must instead be written to the file /etc/mospe.

EXAMPLES

In a basic 2 nodes cluster where the nodes have unrelated IP-addresses (first node address is 200.200.120.5 and the second node address is 200.200.120.10), then your /etc/mosix.map could look like:

1 200.200.120.5 1
2 200.200.120.10 1

If the IP-addresses of the nodes are consecutive (first node address is 200.200.120.5 and the second node address is 200.200.120.6), then your /etc/mosix.map could look like:

1 200.200.120.5 2

If you have 6 nodes, with 3 nodes in class-C internet addresses 200.200.120.xxx, 1 node in addresses 200.200.130.xxx and 2 nodes in addresses 200.200.140.xxx, then your /etc/mosix.map could have the following lines:

1 200.200.120.1 3
4 200.200.130.1 1
5 200.200.140.1 2

In a more complex example, if you have 13 nodes, 6 on a network with IP addresses 192.168.0.xxx, 6 on a network with IP addresses 192.168.1.xxx and one router connecting both networks that uses both IP addresses: 192.168.0.100 and 192.168.1.100, then your /etc/mosix.map could look like:

1 192.168.0.1 6
7 192.168.0.100 1
7 192.168.1.100 ALIAS
8 192.168.1.1 6

SEE ALSO

mosix(7).