logo

Manual Pages


Table of Contents

NAME

na_iswt - access control/status features of the NetApp iSCSI software target (iswt) driver

SYNOPSIS

iswt interface show [ -a | <interface> ... ]

iswt interface enable { -a | <interface> ... }

iswt interface disable [-f] { -a | <interface> ... }

iswt session show [-v | -t | -p] <adapter> [ <session_num> ]

DESCRIPTION

iSCSI is a transport protocol which allows standard SCSI block access over a TCP/IP network. When the iSCSI service is licensed and enabled (see na_iscsi(1)), a Network Appliance filer can operate as an iSCSI target device.

The Data ONTAP iswt driver is a software-only implementation of the iSCSI protocol, which allows the filer to be accessed as an iSCSI target device over the filer's standard network interfaces.

The iswt command allows access to control and status functions supported by the driver.

USAGE

Network Interface Management
The iswt driver allows the filer to be accessed as an iSCSI target device over the filer's standard network interfaces. The iswt interface command allows the administrator to control which network interfaces may be used for iSCSI connectivity. For example, an administrator may wish to configure a filer to support iSCSI access only through the filer's Gigabit ethernet interfaces.

When the iscsi service is enabled and the iswt adapter is online via the iscsi command (see na_iscsi(1)), the iswt driver supports iSCSI access over those network interfaces enabled for its use via the iswt interface command, but not over disabled interfaces. When the iscsi service is stopped or the iswt adapter is offline, then the iswt driver does not allow iSCSI access over any interface, regardless of its enable/disable state.

The iswt interface subcommands are:

iswt interface show [ -a | <interface> ... ]

Show the enable/disable state of the specified interfaces, or of all interfaces if -a is specified. If no arguments are specified at all, the state of all interfaces is displayed.

iswt interface enable { -a | <interface> ... }

Enable use by the iswt driver of the specified interfaces, or of all interfaces if -a is specified.

Once enabled, the iswt driver will begin accepting incoming iSCSI sessions via the newly enabled interfaces.

iswt interface disable [-f] { -a | <interface> ... }

Disable use by the iswt driver of the specified interfaces, or of all interfaces if -a is specified.

The process of disabling an interface requires termination of any outstanding iSCSI sessions currently using that interface. If outstanding iSCSI sessions exist on an interface to be disabled, the command will display a message to notify the administrator and prompt for confirmation prior to proceeding with the disable. The -f option forces termination of any outstanding sessions without prompting for confirmation.

Once disabled, the iswt driver rejects subsequent attempts to establish new iSCSI sessions over that interface.

Session Status
The iswt driver supports multiple simultaneous iSCSI sessions from different iSCSI initiator ports. The iswt session command allows the user to view the state of outstanding sessions.

The iscsi session usage is as follows:

iswt session show [-v | -t | -p] <adapter> [ <session_num> ]

Show status of one session, or for all connections associated with a specified adapter if no session number is specified.

If the -t option is specified, the output contains underlying TCP connection information.

If the -p option is specified, the output contains iSCSI session parameter information.

If the -v option is specified, the output is verbose, and contains all information, including that shown with the -t and -p options.

Status information displayed includes:

Initiator name, ISID - The iSCSI nodename and iSCSI Initiator Session ID, which combine to identify the initiator using this session.

Filer network interface - The name of the network interface over which the session is being conducted.

TCP connections - The IP address and TCP port of the underlying TCP connection.

Session Parameters - iSCSI session parameters negotiated via the iSCSI login key exchanges. For specific definitions of these parameters, please see the iSCSI protocol specification.

CLUSTER CONSIDERATIONS

ISWT driver supports two separate logical "adapters", iswta and iswtb. The iswta logical adapter is dedicated to local host traffic, and supports iSCSI sessions over all of the filer's local host standard network interfaces. The iswtb adapter is dedicated to partner host traffic, and is online only when the filer is operating in takeover mode.

Each session is associated with a specific adapter.

EXAMPLES

iswt interface show

Show iswt enable/disable state of all network interfaces:

    filer*> iswt interface show
    Interface e0 disabled
    Interface e3 enabled
    Interface e5 enabled

iswt interface disable e0 e3

Disable use of specific network interfaces by the iswt driver.

    filer*> iswt interface disable e0 e3
    Interface e0 already disabled

    iSCSI sessions are outstanding over interface e3
    Do you wish to terminate these sessions and disable the interface? yes
    Disabling interface e3

iswt interface enable -a

Enable use of all network interfaces by the iswt driver.

    filer*> iswt interface enable -a
    Enabling interface e0
    Enabling interface e3
    Interface e5 already enabled

iswt session show iswta

Show status for all sessions associated with adapter iswta:

    filer*> iswt session show iswta
    Session 0
      Initiator Name: iqn.2002-05.com:vendor-x.host1
      ISID: 00:00:00:00:00:00
    Session 1
      Initiator Name: iqn.2002-05.com:vendor-x.host1
      ISID: 00:00:00:00:00:01
    Session 27
      Initiator Name: iqn.1999-03.com:vendor-y.host2
      ISID: 00:00:00:00:37:24

iswt session show -v iswta 0

Show verbose status for a specific session:

    filer*> iswt session show -v iswta 0
    Session 0
      Initiator Information
        Initiator Name: iqn.2002-05.com.vendor-x:host1
        ISID: 00:00:00:00:00:00
      Session Parameters
        InitiatorName=iqn.2002-05.com.vendor-x:host1
        InitiatorAlias=
        SessionType=Normal
        ImmediateData=Yes
        InitialR2T=Yes
        MaxOutstandingR2T=1
        HeaderDigest=No
        DataDigest=No
        MaxRecvDataSegmentLength=65536 (Initiator)
        MaxRecvDataSegmentLength=65536 (Target)
        FirstBurstLength=65536
        MaxBurstLength=65536
        MaxConnections=1
        ErrorRecoveryLevel=0
        DefaultTime2Wait=2
        DefaultTime2Retain=20
        DataPDUInOrder=Yes
        DataSequenceInOrder=Yes
        Command Window Size: 32
      TCP Connection Information
        Remote Endpoint: 192.168.0.1:1284
        Local Endpoint: 192.168.0.10:48140
        Local Interface: e5
        TCP recv window size: 131400

SEE ALSO

na_iscsi (1).


Table of Contents