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hboot - Online in the Cloud

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This is the command hboot that can be run in the OnWorks free hosting provider using one of our multiple free online workstations such as Ubuntu Online, Fedora Online, Windows online emulator or MAC OS online emulator



hboot - Start LAM on the local node.


hboot [-dhstvNV] [-c conf] [-I inet_topo] [-R rtr_topo]


-d Turn on debugging. This implies -v.

-h Print the command help menu.

-s Close stdio of child processes.

-t Terminate (tkill(1)) any previous LAM session before starting.

-v Be verbose.

-N Go through the motions but do not actually take any action.

-V Format and print the process schema.

-c conf Use conf as the process schema.

-I inet_topo Set the $inet_topo variable in the process schema.

-R rtr_topo Set the $rtr_topo variable in the process schema.


Most MPI users will probably not need to use the hboot command; see lamboot(1).

The hboot tool can be understood as a generic utility that starts multiple processes on
the local node, based on information in a process schema. It is not restricted to
starting LAM. It is part of the startup sequence preformed by lamboot(1).

A process schema is a description of the processes which constitute the operating system
on a given node. Naturally, the process schema used by hboot should be the one that
describes LAM on a node. The grammar of the process schema is described in conf(5).

When starting LAM on a remote machine using rsh(1), the open file descriptors of the
processes started by hboot must be closed in order for rsh(1) to exit. This is done by
using the -s option. The -t option can be used to force a tkill(1) on the machine before
attempting to start LAM. This feature is used by lamboot(1) to handle the case where a
user might start a machine a second time without using lamwipe(1) to terminate the
previous LAM session.

The -I and -R options set their respective variables to the given values. The $inet_topo
variable is typically used by the LAM Internet datalinks that communicate with other
nodes. The $rtr_topo variable is passed to the LAM router that handles network and
topology information. The variables can also be set in the process schema file (see
conf(5)) but their values are overridden by the command line options.

When LAM is started, the kernel records all processes that attach to it, including all the
processes in the process schema. It is the job of tkill(1) to use this information to
remove these processes from the node.


hboot -v
Start LAM on the local node with the default process schema. Report about every step
as it is done.

hboot -c myconfig
Boot the local node with the custom process schema, myconfig.

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