open-iscsi

This role installs and configures open-iscsi, an iSCSI initiator.

Requirements

Any Debian based system should work, this role is tested on Debian 9.

Role Variables

Variable	Default / Mandatory	Description
open_iscsi_initiator_name	✔️	Name of this initiator name, see iSCSI naming conventions
open_iscsi_automatic_startup	False	Automatically startup a session on service initialization
open_iscsi_leading_login	False	For automatic startup, try login on each available ifaces until one succeeds instead of trying to login on all ifaces simultaneously
open_iscsi_authentication	False	Use CHAP authentication to login into nodes, see Login authentication
open_iscsi_discovery_authentication	False	Use CHAP authentication for discovery, see Discovery authentication
open_iscsi_replacement_timeout	120	Timeout in seconds for session reestablishment before failing SCSI commands. Set to 0 to fail immediately and negative to leave the commands queued until the session is logged back in or manually logged out.
open_iscsi_login_timeout	15	Timeout in seconds to wait for login to complete
open_iscsi_logout_timeout	15	Timeout in seconds to wait for logout to complete
open_iscsi_noop_out_interval	5	Interval in seconds to wait for on connection before sending a ping
open_iscsi_noop_out_timeout	5	Timeout in seconds to wait for a Nop-out response before failing the connection
open_iscsi_abort_timeout	15	Timeout in seconds to wait for an abort response before trying a LUN reset
open_iscsi_lu_reset_timeout	30	Timeout in seconds to wait for a LUN response before failing the operation and trying session re-establishment
open_iscsi_tgt_reset_timeout	30	Timeout in seconds to wait for a target response before failing the operation and trying session re-establishment
open_iscsi_initial_login_retry_max	8	Number of retries after open_iscsi_login_timeout is reached
open_iscsi_cmds_max	128	Number of commands the session will queue, must be a power of two between 2 and 2048.
open_iscsi_queue_depth	32	Device's queue depth, a power of two between 2 and 1024
open_iscsi_thread_priority	-20	Thread priority
open_iscsi_initialR2T	False	Wait for a R2T command before sending data
open_iscsi_immediate_data	True	Send data to target unsolicitedly
open_iscsi_first_burst_length	262144	Maximum number of unsolicited bytes sent in an iSCSI PDU (see open_iscsi_immediate_data), must be between 512 and 2^24-1.
open_iscsi_max_burst_length	16776192	Maximum payload size in bytes to negotiate, must be between 512 and 2^24-1.
open_iscsi_max_recv_length	262144	Maximum payload size the initiator can receive, must be between 512 and 2^24-1.
open_iscsi_max_xmit_length	0	Maximum data bytes to send, must be between 512 and 2^24-1. If set to 0, the initiator will use the target's max_recv_length.
open_iscsi_discovery_max_recv_length	32768	Data bytes the initiator can receive during a discovery session, must be between 512 and 2^24-1.
open_iscsi_header_digest	None	Digest methods to use for the header, see Digests
open_iscsi_data_digest	None	Digest methods to use for data, see Digests
open_iscsi_nr_sessions	1	Number of sessions per iface record. It may be useful to use more than one session for multipath setups.
open_iscsi_fast_abort	True	Do not respond to PDUs after a management function like an ABORT.

Login authentication

These login credentials for logging into targets are only used when open_iscsi_authentication is True and have to be defined in username/password pairs. You can choose to define one or both of the pairs.

Variable	Description
open_iscsi_auth_username	Username to authenticate at the target
open_iscsi_auth_password	Password to authenticate at the target
open_iscsi_auth_username_in	Username to authenticate the target against this initiator
open_iscsi_auth_password_in	Password to authenticate the target against this initiator

Discovery authentication

These login credentials for the discovery phase are only used when open_iscsi_discovery_authentication is True and have to be defined in username/password pairs. You can choose to define one or both of the pairs.

Variable	Description
open_iscsi_discovery_auth_username	Username to authenticate at the target
open_iscsi_discovery_auth_password	Password to authenticate at the target
open_iscsi_discovery_auth_username_in	Username to authenticate the target against this initiator
open_iscsi_discovery_auth_password_in	Password to authenticate the target against this initiator

Digests

Digests can be disabled with None or checked with CRC32C. It's also possible to allow both methods seperated by a comma, depending on the target's ability. If two methods are specified, the first one is the preferred one. E.g. CRC32C,None asks the target to check the digest, but does not enforce it.

Example Playbook

- hosts: hypervisor
  roles:
  - open_iscsi_authentication: True
    open_iscsi_initiator_name: 'iqn.2013-07.de.uni-stuttgart.stuvus.iscsi:hypervisor01'
    open_iscsi_auth_username: hypervisor01
    open_iscsi_auth_password: weef4IeYe0ahPahbe9oj1jia6leiv0jaigaanie1pes4biuB2u

License

This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.

Author Information

• Michel Weitbrecht (SlothOfAnarchy) michel.weitbrecht@stuvus.uni-stuttgart.de