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Run_ssa_link_speed cron, Duplicate node test – Compex Systems Advanced SerialRAID Adapters SA33-3285-02 User Manual

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Redundant power failures in SSA enclosures

The test runs hourly at a specific time in the hour.

run_ssa_link_speed cron

SSA links can run at 20 MB per second or at 40 MB per second. Normally, two SSA
nodes that can communicate at 40 MB per second operate the link between them at 40
MB per second. Some faults, however, can cause a 40-MB-per-second link to run at
only 20 MB per second. The run_ssa_link_speed program detects when a pair of
high-speed nodes are running at low speed. The following entry is added to the cron
table to invoke this program at 04:30 each day:

30 4 * * * /usr/lpp/diagnostics/bin/run_ssa_link_speed 1>/dev/null 2>/dev/null

If the program detects a problem, it sends an error code to the system error log.

You can also use the ssa_speed -x command to check whether any high-speed nodes
are running at low speed (see “ssa_speed Command” on page 369.).

Duplicate Node Test

The node_number attribute of the ssar can be set to enable SSA disk fencing or SSA
target mode operations. It is important, however, that duplicate node numbers do not
exist on the subsystem. Each hour, therefore, the device driver performs a
duplicate-node-number test. If this test finds a duplicate node number, it logs an error
code under the SSA_SETUP_ERROR label. The device driver continues to log this
error each hour until the problem is solved. This test runs separately from the
run_ssa_healthcheck. The test is run hourly but not at any specific time in the hour.

Chapter 11. SSA Error Logs

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