Transport Statistics

Number of ioscan’s issued

I

The total number of times the iSCSI subtree of nodes has been scanned.

Number of Discovery sessions opened

I

The number of discovery sessions that were opened to discover new targets. A discovery session is opened for each iSCSI target port during an ioscan. A single ioscan would therefore result in a separate discovery session for each target port (portal group).

Number of Discovery session open failures

D/C

The number of attempted discovery sessions that failed. The failure is due to an inability to open a connection. Some of the reasons why a connection open might fail are:

Number of Normal sessions opened

I

The number of normal sessions that were opened. Normal sessions are opened to perform I/O. In general, normal sessions are any session other than discovery sessions.

Number of Normal session open failures

D/C

The number of attempted normal/operational sessions that failed. The failure is due to an inability to open a connection. Some of the reasons why a connection open might fail are:

Number of SCSI-3 REPORT LUNs commands issued

I

The number of SCSI-3 REPORT_LUNS commands issued to iSCSI targets during ioscans.

Number of SCSI-3 REPORT LUNs commands issued that failed

D

The number of attempted SCSI-3 REPORT LUNS commands that failed. The failure is due to an incomplete I/O operation or no support for the command by the target. Lack of support for this command is not an error, although it is included in this counter.

Number of SCSI INQUIRY commands issued

I

The number of SCSI INQUIRY commands issued to iSCSI targets during ioscans.

Number of SCSI INQUIRY commands issued that failed

D/C/T

The number of attempted SCSI INQUIRY commands that failed. The failure is due to an incomplete I/O operation.

Number of SendTargets commands issued

I

The number of iSCSI SendTargets commands sent to iSCSI targets. The iSCSI SendTargets command is used in discovery sessions to determine normal targets behind a target port (portal group). Normal sessions can then be established with the normal targets for I/O operations.

Number of SendTargets commands issued that failed

D

The number of iSCSI SendTargets command attempts that failed. The failure is due to an operation time-out which is seen as an incomplete I/O operation.

Number of SendTargets response parse failures

T

The number of iSCSI SendTargets command attempts that failed as a result of a received key parse error. This failure would result from invalid keys received from the target device.

Number of unclaimed LUNs

I

The number of LUNs that will not be seen in an ioscan operation. LUNS are reported to the initiator through the SCSI-3 REPORT LUNS command. All LUNs are viewed, and a primary addressing mode is determined. All LUNs behind a target with a mode that is not the primary addressing mode will not be seen in the ioscan output. Also, LUNs using a multi-level LUN address are not supported and are included in this count.

Number of I/Os that failed due to session being offline

D/C

The total number of I/O requests that failed as a result of a session being offline. This is a global total over all sessions.

Time when statistics were last cleared

I

The time that the statistics were last cleared. This defines the period of time to which the statistics can be applied, and therefore can be used for averaging the statistics. Because each system is different, separate statistic rates can be determined on a per-system basis and used to identify load changes.

Transport Session Statistics

Number of session opens from upper layers

I

The number of session open requests received in the transport layer from upper layer protocols (SCSI).

Number of session closes from upper layers

I

The number of session close requests received in the transport layer from upper layer protocols (SCSI).

Number of session reopens

I

The number of time the ioconfigd (I/O Configuration Daemon) initiates a session reopen.

Number of session opens in the reopen context

I

The number of session open requests received in the transport layer while in the reopen context. A reopen is a component of session error recovery.

Number of session opens aborted in the reopen context

I

The number of session open requests received, while in a reopen context, that were aborted because the session is already open.

Number of session closes aborted in the reopen context

I

The number of session close requests received, while in a reopen context, that were aborted because the session is already closed.

Number of connection opens that failed

C

The number of session open requests received that failed. The failure could have been due to unavailability of resources, or problems with the connection to the target.

Number of successful login redirections

I

The number of times logins were successfully redirected to different target addresses.

Number of async events received for dead connections

C

The number of TCP connections that have been unexpectedly dropped. This is typically a result of connectivity problems. If a problem is persistent, a network infrastructure engineer should be contacted.

Number of destination hostname resolution failures

C

The number of hostname resolution failures. Hostname resolution is performed via the iscsi_resolvd daemon. A hostname resolution failure indicates a network configuration problem.

Number of destination address routing failures

C

The number of destination address routing failures. Destination address routing is performed through host networking. An address routing failure indicates a network configuration problem.

Number of session logouts

I

The number of session logouts performed by the initiator.

Number of session state machine transitions to online state

I

The number of session state machine transitions to the online state.

Number of session state machine transitions to transient state

I

The number of session state machine transitions to the transient state. A session enters the transient state when:

Number of session state machine transitions to offline state

I

The number of session state machine transitions to the offline state.

Number of requests to enable session flow control

I

The number of requests from the network interface driver to enable session flow control for I/Os. This might be the result of excessive I/Os through a session that impacts general network performance.

Number of requests to disable session flow control

I

The number of requests from the network interface driver to disable session flow control for I/Os.

Number of async events "target will drop all connections" received

I

The number of asynchronous requests from the target to perform a session logout.

Number of SendTargets command send failures

D/I/T

The number of PDU send attempts that failed. This could be the result of resource allocation problems or target connectivity issues.

Number of unexpected events received in session online state

D

The number of session state machine unexpected events received while in the online state. The unexpected events will be ignored, and will not impact operations. If this value is non-zero, an investigation into the cause of the unexpected events should be initiated.

Number of unexpected events received in session transient state

D

The number of session state machine unexpected events received while in the transient state. The unexpected events will be ignored, and will not impact operations. If this value is non-zero, an investigation into the cause of the unexpected events should be initiated.

Number of unexpected events received in session offline state

D

The number of session state machine unexpected events received while in the offline state. The unexpected events will be ignored, and will not impact operations. If this value is non-zero, an investigation into the cause of the unexpected events should be initiated.

Number of Task Management commands sent

I

The number of Task Management commands sent by all sessions.

Number of Task Management commands failed

D/T

The number of Task Management commands that failed. The failures could be due to unavailable resources or target connectivity problems.

Number of login failures due to not configuring CHAP secret

D

The number of CHAP authentication configuration errors. CHAP authentication was requested and the initiator secret had not been configured, or had not been correctly configured, by the administrator.

Number of times there was no connection associated with an authentication response

D/C

The number of times a connection has been closed, or logged out, for which the iradd daemon has responded with an authentication response using CHAP.

Number of times the connection signature stamp did not match with the authentication response

I

The number of times a connection has been closed, or logged out, but the associated structures are not freed, for which the iradd daemon has responded with an authentication response using CHAP.

Number of times the target sent a "bad next stage" during login negotiation

T

The number of times the target sent a "bad next stage" during login negotiation. A non-zero value indicates problems were experienced during a login attempt to an iSCSI target. These would typically indicate protocol violations and would not be seen with conforming targets.

Number of login context allocation failures

D

The number of times the iSCSI login context allocation has failed. The failures could be due to unavailable resources.

Number of unsolicited NOP-INs sent by the target

I

The total number of unsolicited NOP-IN PDUs received from the target.