Linux scsi target administration utility
tgtadm [OPTIONS]... [-C --control-port <port>] [-L --lld <driver>] [-o --op <operation>] [-m --mode <mode>] [-t --tid <id>] [-T --targetname <targetname>] [-y --blocksize <size>] [-Y --device-type <type>] [-l --lun <lun>] [-b --backing-store <path>] [-f --bsoflags {direct|sync}] [-S --bsopts {backing-store opt string}] [-E --bstype <type>] [-I --initiator-address <address>] [-Q --initiator-name <name>] [-n --name <parameter>] [-v --value <value>] [-P --params <param=value[,param=value...]>] [-F --force] [-h --help]
tgtadm is used to monitor and modify everything about Linux SCSI target software: targets, volumes, etc.
-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, --blocksize <size>
Block devices are created with a default block size of 512 bytes. This argument can be used to create block devices with different block sizes.
Example:
tgtadm --lld iscsi --mode logicalunit --op new \
--tid <TID> --lun <LUN> \
-b <backing-file> --blocksize=4096
-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
rbd : Use Ceph's distributed-storage RADOS Block Device
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 delete --force --mode target --tid <id>
Delete specific target forcibly with <id>.
--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> --bsopts=<backing store options>
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, or an RBD image or snapshot name for --bstype rbd. lun0 is reserved for a special device automatically created.
Example: If tgt is compiled with the bs_rbd backing store for Ceph RBD images (see tgtadm --mode system --op show to verify), set up a target mapping the rbd image named "rbdimage", and pass options to bs_rbd: tgtadm --lld iscsi --op new --mode logicalunit --tid 1 \ --lun 1 --bstype=rbd --backing-store=rbdimage \ --bsopts="conf=/etc/ceph/ceph.conf;id=tgt"
--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 bind --mode target --tid <id> --initiator-name <name>
Add the initiator's name to the access lists of the target with <id>. Initiators with the names can access to the 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 unbind --mode target --tid <id> --initiator-name <name>
Delete the initiator's name 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 target parameters.
--lld <driver> --op update --mode logicalunit --tid <id> --lun <id> --params parameter=value<,...>
Sets/changes the value of one or more logical unit parameters.
--lld <driver> --op start --mode lld
Start the specified lld without restarting the tgtd process. Can be used to initialize lld driver in case required modules were loaded after tgtd was already executed.
--help
Display a list of available options and exits.
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
thin_provisioning=<0|1>
This controls the provisioning for the LUN. A thin-provisioned LUN is represented as a sparse file. TGTD supports provisioning type 2 for sparse files. When initiators use the SCSI UNMAP command TGTD will release the affected areas back to the filesystem using FALLOC_FL_PUNCH_HOLE.
This parameter only applies to DISK devices.
Thin-provisioning only works for LUNs stored on filesystems that support FALLOC_FL_PUNCH_HOLE.
tgtadm --lld iscsi --mode logicalunit --op update --tid 1 --lun 1 \
--params thin_provisioning=1
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.
clear_slot=<1>
This option is used to clear a storage element and remove any media that may be present. Once this command completes the storage element will show up as "Empty".
barcode=<string>
This is used to assign a barcode to an element. Barcodes are limited to 10 characters in tgtd.
volume_tag=<string>
This is used to assign a volume tag to SMC storage elements. If no volume tag is specified tgtd will use fall back to the barcode. The volume tag can be up to 32 characters.
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,volume_tag="A blank disk",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,volume_tag="My second blank disk",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
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.
--bsoflags={direct|sync}
This argument is used when creating a LUN to specify extra flags to use when opening the backing file. O_DIRECT is specified by "direct" and O_SYNC by "sync".
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 Example: Open the backing file with O_SYNC. tgtadm --lld iscsi --op new --mode logicalunit --tid 1 --lun 1 --bsoflags="sync" --backing-store=/data/100m_image.raw
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.
This command is used to view the current settings for header/data digest.
tgtadm --op show --mode target --tid 1 ... HeaderDigest=None DataDigest=None ...
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
CHAP authentication is supported to require authentication before an initiator is allowed to log in and access devices.
CHAP main-phase authentication is set on the target level. To set up CHAP authentication we first need to create an account and its associated password, then we bind the account to one or more targets.
These two commands create a user account and binds it to target 1.
tgtadm --lld iscsi --op new --mode account --user ronnie --password password tgtadm --lld iscsi --op bind --mode account --tid 1 --user ronnie
This command is used to list all accounts that have been created.
tgtadm --lld iscsi --op show --mode account
Account list:
ronnie
When listing the targets, each target that has authantication enabled will contain a listing of all accoutns bound to that target.
tgtadm --lld iscsi --op show --mode target
Target 1: iqn.ronnie.test
...
Account information:
ronnie
...
TGTD can send NOP-OUT probes to connected initiators to determine when an initiator is dead and then automatically clear and tear down the TCP connection. This can either be set as a global default from the tgtd command-line or it can be set for individual targets using the tgtadm command.
The tgtadm command is used to view the current setting for if/when to send NOP-OUT probes to connected initiators.
If the target is configured to send NOP-OUT probes this will show up as two parameter lines in the target printout. If the target is not configured to send NOP-OUT these lines will not be printed at all.
tgtadm --lld iscsi --op show --mode target
Target 1: iqn.ronnie.test
System information:
Driver: iscsi
State: ready
Nop interval: 5
Nop count: 5
I_T nexus information:
The tgtadm command is used to change the NOP-OUT settings.
tgtadm --op update --mode target --tid 1 -n nop_count -v 5 tgtadm --op update --mode target --tid 1 -n nop_interval -v 5
iSCSI portals can be viewed, added and removed at runtime.
This command is used to list the current iSCSI portals defined on the target:
tgtadm --lld iscsi --op show --mode portal Portal: 10.1.1.101:3260,1 Portal: 127.0.0.1:3260,1
This command is used to add a portal to the target :
tgtadm --lld iscsi --op new --mode portal --param portal=10.1.1.101:3260
This command is used to remove a portal from the target :
tgtadm --lld iscsi --op delete --mode portal --param portal=10.1.1.101:3260
iSCSI connections can be viewed and forced closed at runtime.
This command is used to list the all the active iSCSI connections to the target with connection id, initiator name and ip address for the initiator :
tgtadm --lld iscsi --op show --mode conn --tid 1
Session: 2
Connection: 0
Initiator: iqn.2008-11.org.linux-kvm:
IP Address: 127.0.0.1
This command is used to close an iSCSI connection. Note that forcibly closing iSCSI connections can lead to data-loss.
tgtadm --lld iscsi --op delete --mode conn --tid 1 --sid 2 --cid 0
Tgtd LUNs can be in online or offline status. LUNs that are Offline behave slightly different depending on the device type. Offline devices behave as if there is no media available and any operations that access media will fail with an check-condition error.
Devices can not be set to Offline mode while there are "PREVENT ALLOW MEDIUM REMOVAL" locks on the device. Similarly media in Online devices can not be software ejected while there are such locks on the device (the 'eject' command will fail).
Finding the Online/Offline status of a LUN is done through the tgtd command. If "Prevent removal" is "Yes" this indicates that an application holds a "prevent media removal" lock on the device.
tgtadm --lld iscsi --mode target --op show
...
LUN: 2
Type: cd/dvd
SCSI ID: IET 00010002
SCSI SN: beaf12
Size: 3432 MB, Block size: 1
Online: Yes
Removable media: Yes
Prevent removal: Yes
...
A LUN is changed to Offline status using the tgtadm command. When devices are set Offline these devices will behave as if there is no media loaded into the drive.
Change a LUN to become offline. (no disk in the drive)
tgtadm --tid 1 --lun 2 --op update --mode logicalunit -P Online=No
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
tgtd(8), tgt-admin(8), tgtimg(8), tgt-setup-lun(8). \m[blue]http://stgt.sourceforge.net/\m[]
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