$ Linux Command

Network

iscsiadm

Manage iSCSI connections and targets.

iscsistoragesannetworktarget

Additional Notes

iscsiadm is the command-line interface for the Open-iSCSI initiator, which connects Linux systems to iSCSI storage targets over a network. It handles discovery, login, logout, session management, and configuration of iSCSI connections.

iSCSI (Internet Small Computer System Interface) allows a system to access remote block storage devices as if they were local disks. The iscsiadm command manages the iSCSI initiator on the client side, communicating with the kernel's iSCSI subsystem and the iscsid daemon. It supports discovery of targets via SendTargets, iSNS, and static configuration.

Syntax

iscsiadm [options] operation [target-parameters]

Parameters

  • operation: The action to perform (e.g., --mode discovery, --mode node --login, --mode session).

Common Options and Operations

  • -m discovery, --mode discovery: Discover available targets.
  • -m node, --mode node: Operate on stored target records.
  • -m session, --mode session: Manage active sessions.
  • -m iface, --mode iface: Manage iSCSI interfaces.
  • -m host, --mode host: Manage iSCSI host adapters.
  • -t type, --type type: Discovery type (sendtargets, slp, isns).
  • -p ip:port, --portal ip:port: Specify the target portal address.
  • -l, --login: Log in to the target.
  • -u, --logout: Log out from the target.
  • -o operation, --op operation: Database operation (new, delete, update, show).
  • -T target-name, --targetname target-name: Specify the iSCSI target name (IQN or EUI).
  • -n name, --name name: Specify a record or field name for configuration.
  • -v value, --value value: Set the value for a configuration field.
  • -I iface-name, --interface iface-name: Use a specific iSCSI interface binding.
  • -P level, --print level: Set the print verbosity level (0-4).

Examples

sudo iscsiadm -m discovery -t sendtargets -p 192.168.1.100

Discover available iSCSI targets on the portal at 192.168.1.100.

sudo iscsiadm -m node -T iqn.2023-01.com.example:storage.target01 -p 192.168.1.100 -l

Log in to a specific iSCSI target.

sudo iscsiadm -m session

Show all active iSCSI sessions.

sudo iscsiadm -m node -u

Log out from all logged-in targets.

sudo iscsiadm -m node -o delete -T iqn.2023-01.com.example:storage.target01

Remove a target's record from the node database.

iscsiadm -m session -P 3

Show detailed session information including connections and parameters.

Practical Notes

  • The iscsid daemon must be running for iscsiadm to function. Start it with systemctl start iscsid.
  • After logging in to an iSCSI target, the block devices appear as /dev/sd*, /dev/mapper/*, etc.
  • Use lsblk or fdisk -l to identify new disks after login.
  • To make iSCSI connections persistent, set node.startup = automatic with iscsiadm -m node -T TARGET -o update -n node.startup -v automatic.
  • iSCSI targets are identified by IQN (iSCSI Qualified Name) format: iqn.YEAR-MONTH.reverse.domain:identifier.
  • The configuration database is stored in /etc/iscsi/ and can be manually edited if needed.
  • For multipath iSCSI, use device-mapper-multipath together with iscsiadm.