IBM RS/6000 SP Problem Determination Manual page 126

This soft copy for use by IBM employees only.
distributed. The cleanup of the /etc/SP/expected.top is not carried out for this
switch. If there has been a change, then the new topology file is copied into
/etc/SP on the primary. This topology file is further distributed on to the nodes
(through the boot/install servers, if there are any).
Eclock
- Controls the clock source for each switch board within a RS/6000 SP.
The clock source topology file (located in /etc/SP on Control Workstation) is
Eclock
selected during installation of the system. uploads the mux values to
each switch board, which tells it where it will get its clock source, and then does
a reset on the board to resynchronize the switch chips. This is disruptive to
normal operations on the switch and care should be taken when this command
is run so that data is not corrupted or lost.
Efence
- Removes a SP node from the current active switch network.
For the High Performance Switch after a request to fence a node is issued, the
switch adapter is flagged that the request has been made to come off the switch
network. The Worm on the primary node is notified by a service packet during
service phase (see Eduration below), and it creates a new routing table based on
the fact that the link to the node is not included. The Worm on the primary then
distributes these to the nodes. In this way the link to the node is disabled. The
nodes are not able to generate a switch fault by sending a packet to the fenced
node, and so the switch fabric does not get disrupted.
With the SP Switch, the routes are not distributed over the network; only the
changes to the device database are. This database contains a listing of the
active nodes for that partition (that is, it does not include nodes that are fenced
or off the network). If a node is fenced with the autojoin option, then it is
included in the list of active nodes because it is ready to rejoin the network at
the next Estart. Any disabled links will be also flagged in this database. The
primary Worm will then generate a new routing table to download onto its SRAM
on the TB3 adapter. It will communicate the changes in the database as a delta
(that is, it will not send the entire database) to the other nodes. The Worm
daemons on the nodes are able to compute the routes locally for loading onto
the SRAM on the switch adapters.
Eunfence
- Adds a SP node to the current active switch network that was previously
Efence
removed with the command.
Efence Eunfence
and allow you to plan maintenance on a node and smoothly take
it on- and off-line with minimal effect on the switch network. By default, every
two minutes the switch network goes into service phase and looks for a node to
Eduration
fence or unfence (see ).
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