IBM RS/6000 SP Selecting appropriate switch clocks, Selecting the switch clock source, Eclock

v″Yes″ displayed in a red box indicates that the switch supervisor has failed and it is not responding to the frame supervisor.

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Selecting appropriate switch clocks

The following procedure describes how to select a clock source for a switch assembly, followed by an explanation on how to determine which clock source to use on each assembly.

Attention: Changing switch clocks will interrupt use of the switch feature; therefore, switch clocks should be reselected only due to a component failure or scheduled service of part of the machine. Even momentary interruption of the switch clocks (which occurs when reselecting switch clocks), might require recovery step(s) to bring all the processor nodes on-line. In this case, use of all processor nodes in the frame or frame(s) might be interrupted during the recovery procedure.

Selecting the switch clock source

1.Manual method for any SP system: From an AIX window, enter:

spmon -G -m i framex spmon -G -m 1 framex spmon -G -m 2 framex spmon -G -m 3 framex

2.Topology file method:

a.From an AIX window, enter:

Eclock

(The display will tell you the current clock topology.)

b.To select an alternate clock topology, enter: Eclock -afilename

Refer to IBM RS/6000 SP: Command and Technical Reference for more information on the correct file name to use.

Determining the correct switch clock source

All switch assemblies in the system must run off the same clock source. The following procedure describes how to determine the correct clock settings for each switch assembly based on standard cabling configurations:

1.Determine the number of logical frames in the system.

2.Determine which clock choice to use for the system.

3.Locate the appropriate box in Table 3-4 on page 3-7,using the number of logical frames and the master clock choice.

4.Based on information in this box, set the switch clock source for each logical frame. Lxx- represents the logical frame number

Sxx- represents a multi-switch frame

i or 0, 1, 2, or 3 indicates the appropriate clock setting for that logical frame: i or 0 Internal Clock (SPS)

3-6RS/6000 SP: SP Switch Service Guide