1.\" Copyright (c) 2014 Edward Tomasz Napierala 2.\" All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 13.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 14.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 15.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 16.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 17.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 18.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 19.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 20.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 21.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 22.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 23.\" SUCH DAMAGE. 24.\" 25.\" $FreeBSD$ 26.Dd May 28, 2017 27.Dt ISCSI 4 28.Os 29.Sh NAME 30.Nm iscsi 31.Nd iSCSI initiator 32.Sh SYNOPSIS 33To compile this driver into the kernel, 34place the following line in the 35kernel configuration file: 36.Bd -ragged -offset indent 37.Cd "device iscsi" 38.Ed 39.Pp 40Alternatively, to load the driver as a 41module at boot time, place the following line in 42.Xr loader.conf 5 : 43.Bd -literal -offset indent 44iscsi_load="YES" 45.Ed 46.Sh DESCRIPTION 47The 48.Nm 49subsystem provides the kernel component of an iSCSI initiator, 50responsible for implementing the Full Feature Phase of the iSCSI protocol. 51The initiator is the iSCSI client, which connects to an iSCSI target, 52providing local access to a remote block device. 53The userland component is provided by 54.Xr iscsid 8 55and both the kernel and userland are configured using 56.Xr iscsictl 8 . 57.Sh SYSCTL VARIABLES 58The following variables are available as both 59.Xr sysctl 8 60variables and 61.Xr loader 8 62tunables: 63.Bl -tag -width indent 64.It Va kern.iscsi.debug 65Verbosity level for log messages from the 66.Nm 67driver. 68Set to 0 to disable logging or 1 to warn about potential problems. 69Larger values enable debugging output. 70Defaults to 1. 71.It Va kern.iscsi.ping_timeout 72The number of seconds to wait for the target to respond to a NOP-Out 73PDU. 74In the event that there is no response within that time the session gets 75forcibly restarted. 76Set to 0 to disable sending NOP-Out PDUs. 77Defaults to 5. 78.It Va kern.iscsi.iscsid_timeout 79The number of seconds to wait for 80.Xr iscsid 8 81to establish a session. 82After that time 83.Nm 84will abort and retry. 85Defaults to 60. 86.It Va kern.iscsi.login_timeout 87The number of seconds to wait for a login attempt to succeed. 88After that time 89.Nm 90will abort and retry. 91Defaults to 60. 92.It Va kern.iscsi.maxtags 93The maximum number of outstanding IO requests. 94Defaults to 255. 95.It Va kern.iscsi.fail_on_disconnection 96Controls the behavior after an iSCSI connection has been dropped due to 97network problems. 98When set to 1, a dropped connection causes the iSCSI device nodes 99to be destroyed. 100After reconnecting, they will be created again. 101By default, the device nodes are left intact. 102While the connection is down all input/output operations are suspended, to be 103retried after the connection is reestablished. 104.El 105.Sh SEE ALSO 106.Xr iser 4 , 107.Xr iscsi.conf 5 , 108.Xr iscsictl 8 , 109.Xr iscsid 8 110.Sh HISTORY 111The 112.Nm 113subsystem first appeared in 114.Fx 10.0 . 115.Sh AUTHORS 116The 117.Nm 118subsystem was developed by 119.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org 120under sponsorship from the FreeBSD Foundation. 121