IBM Midrange System DS4000 Series Hardware Manual page 431

PCHOC Port Connections Held Off Count (PCHOC) is the number of times the
port attempted to make a connection but it was held off by a busy port.
PUP Port Utilization Percentage (PUP) is the percentage of time that
frames are seen on the port, or percentage of time that a port is used if
in switching mode.
During loop initialization (LIP), the SOC chips temporarily change to hub mode to allow all
devices to see each other in an environment resembling a simple arbitrated loop topology.
This skews some of the error statistics. Therefore, they can only be treated as reliable after a
period of normal activity when no devices have been added, removed, or changed on the
drive-side channels.
Capture State Information
This is a collection of shell commands executed on each controller. It can be started from the
Storage Manager Subsystem Management window by selecting Advanced 
Troubleshooting  Capture State Information. A large uncompressed text file is generated
with a .dmp file name suffix.
This file is also included in the Collect all Support Data bundle.
Each command appears twice within the Capture State Information file, once on each
controller. Each command is shown on a separate line with the following syntax:
Executing <command> on controller <A or B>
The file includes a few commands that might be useful for investigating drive-side problems:
fcDump
chAll
luAll
showEnclosuresPage81 This provides data similar to the SOC statistics file with a few
An incrementing number of fc exchange errors suggests that
there is a problematic device on the loop. This is often a quick
and easy check that can be carried out after excluding a suspect
device from the loop.
Similar output to fcDump, just in a slightly different format.
This command provides a summary of logical unit information.
For our purposes, the important information is in the ORP and
Channels columns. ORP represents Operation, Redundancy and
Performance. These normally are +++ for all disk devices. The
Channels column displays a + for the preferred path to the device
and * for the alternate path.
additional items.
Chapter 7. Advanced maintenance, troubleshooting, and diagnostics
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