TGTADM

OPTIONS

-C, --control-port <port>

It is possible to run multiple concurrent instances of tgtd on a host. This argument is used to control which instance the tgtadm command will operate on.

-Y, --device-type <type>

When creating a LUN, this parameter specifies the type of device to create. Default is disk.

Possible device-types are:
    disk    : emulate a disk device
    tape    : emulate a tape reader
    ssc     : same as tape
    cd      : emulate a DVD drive
    changer : emulate a media changer device
    pt      : passthrough type to export a /dev/sg device
      

-E, --bstype <type>

When creating a LUN, this parameter specifies the type of backend storage to to use.

Possible backend types are:
    rdwr    : Use normal file I/O. This is the default for disk devices
    aio     : Use Asynchronous I/O
    mmap    : Use memory mapping for the backend file

    sg      : Special backend type for passthrough devices
    ssc     : Special backend type for tape emulation
      

--lld <driver> --op new --mode target --tid <id> --targetname <name>

Add a new target with <id> and <name>.

--lld <driver> --op delete --mode target --tid <id>

Delete specific target with <id>. The target must have no active I_T nexus.

--lld <driver> --op show --mode target

Show all the targets.

--lld <driver> --op show --mode target --tid <id>

Show target parameters of a target with <id>.

--lld <driver> --op new --mode logicalunit --tid <id> --lun <lun> --backing-store <path>

Add a new logical unit with <lun> to specific target with <id>. The logical unit is offered to the initiators. <path> must be block device files (including LVM and RAID devices) or regular files. lun0 is reserved for a special device automatically created.

--lld <driver> --op delete --mode logicalunit --tid <id> --lun <lun>

Delete specific logical unit with <lun> that the target with <id> has.

--lld <driver> --op bind --mode target --tid <id> --initiator-address <address>

Add the address to the access lists of the target with <id>. Initiators with the address can access to the target. 'ALL' is a special address to allow all initiators to access to a target.

--lld <driver> --op unbind --mode target --tid <id> --initiator-address <address>

Delete the address from the access lists of the target with <id>.

--lld <driver> --op update --mode target --tid <id> --name=<parameter> --value=<value>

Change the value of <parameter> of the target with <id> to <value>.

--lld <driver> --op update --mode target --tid <id> --params parameter=value<,...>

Sets/changes the value of one or more parameters.

--help

Display a list of available options and exits.

LUN PARAMETERS

These parameters are only applicable for "--mode logicalunit".

vendor_id=<string>

This parameter sets the Vendor Identification string that a LUN will report in INQURY data.

product_id=<string>

This parameter sets the Product Identification string that a LUN will report in INQURY data.

product_rev=<string>

This parameter sets the Product Revision string that a LUN will report in INQURY data.

Example:

tgtadm --lld iscsi --mode logicalunit --op update \
       --tid <TID> --lun <LUN> \
       --params vendor_id=TGTD,product_id=VirtualHD,product_rev=0103
      

removable=<0|1>

This can be used to override/change the default setting for the removable flag. Disk devices default to non-removable while DVD and TAPE devices default to removable.

sense_format=<0|1>

This flag controls the format of sense data that the device will return. 0 = Clasic sense format, 1 = Support descriptor format.

online=<0|1>

This controls whether a device is online or not.

Devices default to be online when created but can be brought offline using this parameter. Behaviour of offline devices depend on device type. An MMC/DVD device that is offline will report that there is no disk in the unit but the actual MMC/DVD unit itself can still be communicated with. All other device types will fail all I/O with a sense code of Not Ready.

Example:

tgtadm --lld iscsi --mode logicalunit --op update \
       --tid 1 --lun 1 \
       --params removable=1,sense_format=1,online=1
      

mode_page=<byte-string>

This parameter is used to set specific mode pages for the device and the mode page contents. Most devices default to reasonable default mode pages automatically when the LUN is created, but this allows special settings.

Examples:

Create mode page '2', subpage 0 and 14 bytes of data.
This is Disconnect-Reconnect mode page.

tgtadm --mode logicalunit --op update --tid 1 --lun 2 \
         --params mode_page=2:0:14:0x80:0x80:0:0xa:0:0:0:0:0:0:0:0:0:0


Create mode page '10', subpage 0 and 10 bytes of data.
This is Control Extension mode page.

tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 \
         --params mode_page=10:0:10:2:0:0:0:0:0:0:0:2:0


Create mode page '0x1c', subpage 0 and 10 bytes of data.
This is Informational Exceptions Control mode page.

tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 \
         --params mode_page=0x1c:0:10:8:0:0:0:0:0:0:0:0:0
      

readonly=<0|1>

This sets the read-only flag of a LUN. A read-only LUN will refuse any attempts to write data to it.

This parameter only applies to DISK devices.

tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 1 \
         --params readonly=1
      

SMC SPECIFIC LUN PARAMETERS

These parameters are only applicable for luns that are of type "changer" i.e. the media changer device for a DVD Jukebox or a Virtual Tape Library.

element_type=<1|2|3|4>

This controls which type of element a certain slot in the jukebox/vtl is.

Slot types:
 1 -> Medium Transport (picker arm)
 2 -> Storage Element
 3 -> Import/Export Element
 4 -> Data Transfer device (CD drive, tape drive, MO drive etc)
          

address=<1-65535>

This is used to create/operate on a single slot. Address specifies the slot on which to perform the operation.

start_address=<1-65535>,quantity=<1--65535>

This is used to create/operate on an entire range of slots at once. Start_address specifies the first address to operate on and quantity specifies the number of consequtive slots.

sides=<1|2>

When creating storage elements, i.e. "element_type=2", this parameter specifies if the media has 1 or two sides to hold data.

barcode=<string>

This is used to assign a barcode to an element.

media_home=<string>

This parameter specifies a directory where all virtual media for the dvd/tape device elements are stored.

To assign a media image file to a storage element slot, you assign "barcode" to be the name of the image file in the "media_home" directory.

Example: How to create a DVD jukebox with eight disk trays and
two empty DVD-R disks.


# Create a target
tgtadm --lld iscsi --mode target --op new --tid 1 --targetname iqn.2007-03:virtual-dvd:`hostname`

# Create a DVD drive and give it a nice name
# The dvd starts out without a backing store file, i.e. no disk loaded
tgtadm --op new --mode logicalunit --tid 1 --lun 1 --device-type cd
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 1 --params vendor_id=STGT_DVD,product_id=DVD101,product_rev=0010,scsi_sn=STGTDVD01,removable=1

# We need a backend store file for the media changer
if [ ! -f $HOME/smc ]; then
        dd if=/dev/zero of=$HOME/smc bs=1k count=1
fi

# Create the SMC device and give it a nice name
tgtadm --lld iscsi --mode logicalunit --op new --tid 1 --lun 2 --backing-store $HOME/smc --device-type changer
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params vendor_id=STK,product_id=L700,product_rev=0010,scsi_sn=XYZZY_0,removable=1

# Add a Data Transfer devices (1 drive)
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params element_type=4,start_address=1,quantity=1

# Specify that the DVD above (LUN 1) is the data transfer device we created
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params element_type=4,address=1,tid=1,lun=1

# Medium Transport Elements (robot arm / picker)
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params element_type=1,start_address=16,quantity=1

# define path to virtual media
VTL=${HOME}/vtl
mkdir -p ${VTL}
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params media_home=${VTL}

# Storage Elements - 8 starting at addr 1024
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params element_type=2,start_address=1024,quantity=8

# Add 'media' to slots 1 and 2 and leave the other 6 slots empty
# slot 1
# Create empty writeable virtual DVD-R media
tgtimg --op new --device-type cd --type dvd+r --file ${VTL}/DISK_001
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params element_type=2,address=1024,barcode=DISK_001,sides=1

# slot 2
tgtimg --op new --device-type cd --type dvd+r --file ${VTL}/DISK_002
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 2 --params element_type=2,address=1025,barcode=DISK_002,sides=1

# Allow ALL initiators to connect to this target
tgtadm --lld iscsi --mode target --op bind --tid 1 --initiator-address ALL

# Show all our good work.
tgtadm --lld iscsi --mode target --op show
      

PASSTHROUGH DEVICES

In addition to device emulation TGTD also supports utilizing existing SG devices on the host and exporting these through a special passthrough device type.

--bstype=sg

This specifies that an SG devices is used.

--device-type=pt

This specifies that passthrough device type is used.

--backing-store=</dev/sg4>

This specifies which device to export through TGTD.

Example:
Make /dev/sg4 available to initiators connecting to TGTD.

tgtadm --lld iscsi --op new --mode logicalunit --tid 1 --lun 1 --bstype=sg --device-type=pt --backing-store=/dev/sg4
    

HEADER DIGEST AND DATA DIGEST

Header and data digests can be set on a per target parameter. TGTD supports two modes, None and CRC32C. When the digest is set to None, TDTD will negotiate that digests will not be used, and when CRC32C is set, TGTD will force the connection to use digest.  

Viewing the current settings

This command is used to view the current settings for header/data digest.

tgtadm --op show --mode target --tid 1
  ...
  HeaderDigest=None
  DataDigest=None
  ...
      

Setting digest

Set header digest to CRC32C:
tgtadm --op update --mode target --tid 1 -n HeaderDigest -v CRC32C

Set data digest to None:
tgtadm --op update --mode target --tid 1 -n DataDigest -v None
      

ISNS PARAMETERS

iSNS configuration for a target is by using the tgtadm command.

iSNSServerIP

This specifies the IP address of the iSNS server. TGTD only supprots one iSNS server.

Example:

tgtadm --op update --mode sys --name iSNSServerIP --value 192.168.11.133
      

iSNS

This setting enables(on)/disables(off) iSNS.

Example:

tgtadm --op update --mode sys --name iSNS --value On
      

iSNSServerPort

This setting specifies the port to use for iSNS.

Example:

tgtadm --op update --mode sys --name iSNSServerPort --value 3205
      

iSNSAccessControl

Enable/disable access control for iSNS.

Example:

tgtadm --op update --mode sys --name iSNSAccessControl --value Off
      

SEE ALSO

tgtd(8), tgt-admin(8), tgtimg(8), tgt-setup-lun(8). m[blue]http://stgt.sourceforge.net/m[]  

REPORTING BUGS

Report bugs to <stgt@vger.kernel.org>

Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

LUN PARAMETERS

SMC SPECIFIC LUN PARAMETERS

PASSTHROUGH DEVICES

HEADER DIGEST AND DATA DIGEST

Viewing the current settings

Setting digest

ISNS PARAMETERS

SEE ALSO

REPORTING BUGS