HP-UX iSCSI Software Initiator Support Guide, HP-UX 11i v1 and 11i v2, July 2005

Appendix D
iSCSI Software Interface Driver Statistics
iSCSI Software Interface Driver Statistics
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Number of I/O underflows I The number of I/Os on a connection where the
target sent less data than what was requested
by the initiator. A large value for this statistic
is normal.
Number of I/O overflows I The total number of I/Os on a connection
where the target sent more data than what
was requested by the initiator. This indicates
that the Expected Data Transfer Length in
the I/O request was not sufficient.
Number of I/O failures due to
response code errors
T The total number of I/Os that failed due to a
response code error in the SCSI response
PDU. This means that the target failed to
execute the I/Os. A large value here could
indicate that the target is not functioning
properly.
Number of Data-In PDUs
received without data
I The total number of empty Data-In PDUs
received by the initiator.
Number of invalid R2T PDUs
received
T The total number of Request to Transfer
(R2T) PDUs from the target that had an
incorrect buffer offset or Data Transfer
Length in them. A non-zero value for this stat
indicates that the target is not adhering to the
error recovery policy negotiated by the
initiator.
Number of I/Os that failed to
respond to an R2T due to kernel
memory allocation failures
D The total number of Request to Transfer
(R2T) PDUs that could not be honored by the
initiator due to resource constraints at the
initiator. A non-zero value for this stat
indicates that the initiator is intermittently
running out of resources while handling iSCSI
I/O traffic.
Number of I/O failures due to
streams message concatenation
memory allocation failures
D The total number of I/O failures in the
inbound path resulting from a failure of
msgpullup call.
Number of holes seen in the
status sequencing
D/T The total number of PDUs that were received
where the status sequence number of the
PDU does not match the expected status
sequence number. For error recovery level
zero, this will cause the initiator to do a
Session level logout.
Number of SCSI Async events
received
I The number of asynchronous events received
by the initiator.
Table D-1 Software Interface Driver Statistics (Continued)
iscsiutil Statistic CL Description of Field