tgtadm(8)

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".

.RE

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


    

.SH "HEADER DIGEST AND DATA DIGEST"

.PP 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.

.SS "Viewing the current settings"

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

tgtadm --op show --mode target --tid 1


  ...


  HeaderDigest=None


  DataDigest=None


  ...


      

.SS "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


      

.SH "CHAP AUTHENTICATION"

.PP CHAP authentication is supported to require authentication before an initiator is allowed to log in and access devices.

.PP 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.

.SS "Setting CHAP on a target"

.PP 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


      

.SS "List all accounts"

.PP This command is used to list all accounts that have been created.

tgtadm --lld iscsi --op show --mode account
Account list:


    ronnie


      

.SS "Show if a target requires authentication"

.PP 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
...


      

.SH "NOP-OUT PROBES"

.PP 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.

.SS "Check the current NOP-OUT setting"

.PP The tgtadm command is used to view the current setting for if/when to send NOP-OUT probes to connected initiators.

.PP 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:


     

.SS "Setting NOP-OUT for a target"

.PP 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


     

.SH "ISCSI PORTALS"

.PP iSCSI portals can be viewed, added and removed at runtime.

.SS "List portals"

.PP 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


      

.SS "Add portal"

.PP 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


      

.SS "Remove portal"

.PP 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


      

.SH "ISCSI CONNECTIONS"

.PP iSCSI connections can be viewed and forced closed at runtime.

.SS "List all active connections for a target"

.PP 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


      

.SS "Close an existing connection"

.PP 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


      

.SH "ONLINE/OFFLINE STATUS"

.PP 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.

.PP 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).

.SS "Show Online/Offline status"

.PP 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
...


      

.SS "Changing a LUN to Offline"

.PP 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.

.PP Change a LUN to become offline. (no disk in the drive)

tgtadm --tid 1 --lun 2 --op update --mode logicalunit -P Online=No


      

.SH "ISNS PARAMETERS"

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

.PP iSNSServerIP

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


      

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


      

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


      

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