SN(1)                                                                    SN(1)


NAME
     sn - NUMA Memory Management Configuration Tool

SYNOPSIS
     sn [-vsah]
        [-m on|off|fon|foff]
        [-t threshold]
        [-z distance]
        [-u on|off]
        [-p threshold]
        [-w interval]
        [-i on|off]
        [-f factor]
        [-r on|off|fon|foff]
        [node-path]


DESCRIPTION
     The current Origin 2000/200 configuration parameters are set according to
     specifications and/or displayed for the given node-path or all nodes in
     the system. Setting these parameters on other Origin platforms has no
     effect.


OPTIONS
     -v   Show all configuration parameters.

     -s   Silent operation. Just set specified parameters.

     -a   Apply requested operation to all nodes in the system.

     -h   Print brief usage summary.

     -m on|off|fon|foff
          Set the default dynamic migration mode; on sets the default to
          migration enabled and users can override the default on a per
          address space basis; off sets the default to migration off and users
          can override the default on a per address space basis; foff
          completely disables migration and fon forces migration to be
          enabled.

     -t threshold
          Set the dynamic migration threshold to threshold. This threshold  is
          a percentage of the maximum possible difference between a local and
          a remote memory reference counter.

     -z distance
          Set the cutoff distance for migration to distance. This is the
          minimum distance between a source and a destination node required
          for migration to take place.


     -u on|off
          Turn the memory reference counter unpegger on/off.

     -p threshold
          Set the pegged level to threshold. This threshold is a percentage of
          the maximum count a memory reference counter can hold.

     -w interval
          Set the unpegger period to interval. This interval is in seconds and
          specifies how often the unpegger should be waken up to check the
          memory reference counters in every node, and reset those counters
          that have reached a pegged level.

     -i on|off
          Enable or disable migration dampening.

     -f factor
          Set the migration dampening factor. This factor is a percentage of
          the maximum possible dampening factor (4 for Origin 2000 systems).

     -r on|off|fon|foff
          Set the default reference counting mode; on sets the default to
          enabled and users can override the default on a per address space
          basis; off sets the default to disabled and users can override the
          default on a per address space basis; foff completely disables
          reference counting and fon forces reference counting to be enabled.

EXAMPLE
     To turn migration off for all nodes:
        $ sn -a -m off
     To turn migration on with a threshold of 34%:
        $ sn -a -m on -t 34

     To enable the extended reference counters on all nodes:
        $ sn -a -r on


RESTRICTIONS
     Only the superuser or users with the MEMORY_MGT capability are allowed to
     use this command to change numa parameters.

SEE ALSO
     numa(5), refcnt(5), gr_sn(1), nstats(1), gr_nstats(1), linkstat(1),
     xbstat(1m), hwgraph(4).


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