IBM RS/6000 SP - Manual (Page 76)

v ″
Yes
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displayed in a red box indicates that the switch supervisor has failed and it is not
responding to the frame supervisor.
Note: Clicking
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Help
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in the Notebook window’s lower right corner displays attribute descriptions.
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 -a filename
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.
L xx- represents the logical frame number
S xx- 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)
3-6 RS/6000 SP: SP Switch Service Guide