Managing the iSCSI SAN

Displaying statistics for iSCSI sessions

Displaying iSCSI statistics  

To display iSCSI statistics, complete the following step.

iscsi stats

Statistics for adapter iswta

iSCSI PDUs Received

  SCSI-Cmd: 0  | Nop-Out:   0  | SCSI TaskMgtCmd: 0

  LoginReq: 0  | LogoutReq: 0  | Text Req:        0

  DataOut:  0  | SNACK:     0  | Unknown:         0

  Total: 0

iSCSI PDUs Transmitted

  SCSI-Rsp: 0 | Nop-In:     0    | SCSI TaskMgtRsp: 0

  LoginRsp: 0 | LogoutRsp:  0    | TextRsp:         0

  Data_In:  0 | R2T:        0    | Asyncmsg:        0

  Reject: 0

  Total:  0

iSCSI CDBs

  DataIn Blocks:           0  | DataOut Blocks:          0

  Error Status:            0  | Success Status:          0

  Total CDBs: 0

iSCSI ERRORS

  Failed Logins:           0  | Failed TaskMgt:          0

  Failed Logouts:          0  | Failed TextCmd:          0

  Protocol:                0

  Digest:                  0

  Unexpected session disconnects:      0

  PDU discards (outside CmdSN window): 0

  PDU discards (invalid header):       0

Interpreting iSCSI statistics  

The iscsi stats command displays the following statistics:

iSCSI PDUs Received

This section lists the iSCSI Protocol Data Units (PDUs) sent by the initiator. It includes the following statistics:

• SCSI-CMD--SCSI-level command descriptor blocks.
• LoginReq--Login request PDUs sent by initiators during session setup.
• DataOut--PDUs containing write operation data that did not fit within the PDU of the SCSI command. The PDU maximum size is set by the filer during the operation negotiation phase of the iSCSI login sequence.
• Nop-Out--A message sent by initiators to check whether the target is still responding.
• Logout-Req--A request sent by initiators to terminate active iSCSI sessions.
• SNACK--Serial Number Acknowledge requests sent by initiators to request retransmission of PDUs previously sent by the target.

  Note
  This release of Data ONTAP does not support SNACK messages.

• SCSI TaskMgtCmd--SCSI-level task management messages, such as ABORT_TASK and RESET_LUN.
• Tex-Req--Text request PDUs that initiators send to request target information and renegotiate session parameters.

iSCSI PDUs transmitted

This section lists the iSCSI PDUs sent by the filer and includes the following statistics:

• SCSI-Rsp--SCSI response messages.
• LoginRsp--Responses to login requests during session setup.
• DataIn--Messages containing data requested by SCSI read operations.
• Nop-In--Responses to initiator Nop-Out messages.
• Logout-Rsp--Responses to Logout-Req messages.
• R2T--Read to transfer messages indicating that the target is ready to receive data during a SCSI write operation.
• SCSI TaskMgtRsp--Responses to task management requests.
• TexRsp--Responses to Tex-Req messages.
• Asyncmsg--Messages the target sends to asynchronously notify the initiator of an event, such as the termination of a session.
• Reject--Messages the target sends to report an error condition to the initiator, for example:
  • Data Digest Error (checksum failed)
  • Target does not support command sent by the initiator
  • Initiator sent a command PDU with an ivalid PDU field

iSCSI CDBs

This section lists statistics associated with the handling of iSCSI Command Descriptor Blocks, including the number of blocks of data transferred, and the number of SCSI-level errors and successful completions.

iSCSI Errors

This section lists login failures, session disconnects, and other SCSI protocol errors.

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Part No. 210-00338
File: c6sanm10.htm
Last updated: 01/17/03 17:40:41