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 July 11, 2015 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. 50The initiator is the iSCSI client, which connects to an iSCSI target, 51providing local access to a remote block device. 52The userland component is provided by 53.Xr iscsid 8 54and both the kernel and userland are configured using 55.Xr iscsictl 8 . 56The 57.Nm 58subsystem is responsible for implementing the 59.Qq Full Feature Phase 60of the iSCSI protocol. 61.Sh SYSCTL VARIABLES 62The following variables are available as both 63.Xr sysctl 8 64variables and 65.Xr loader 8 66tunables: 67.Bl -tag -width indent 68.It Va kern.iscsi.debug 69Verbosity level for log messages from the 70.Nm 71driver. 72Set to 0 to disable logging or 1 to warn about potential problems. 73Larger values enable debugging output. 74Defaults to 1. 75.It Va kern.iscsi.ping_timeout 76The number of seconds to wait for the target to respond to a NOP-Out 77PDU. 78In the event that there is no response within that time the session gets 79forcibly restarted. 80Set to 0 to disable sending NOP-Out PDUs. 81Defaults to 5. 82.It Va kern.iscsi.iscsid_timeout 83The number of seconds to wait for 84.Xr iscsid 8 85to establish a session. 86After that time 87.Nm 88will abort and retry. 89Defaults to 60. 90.It Va kern.iscsi.login_timeout 91The number of seconds to wait for a login attempt to succeed. 92After that time 93.Nm 94will abort and retry. 95Defaults to 60. 96.It Va kern.iscsi.maxtags 97The maximum number of outstanding IO requests. 98Defaults to 255. 99.It Va kern.iscsi.fail_on_disconnection 100Controls the behavior after an iSCSI connection has been dropped due to 101network problems. 102When set to 1, a dropped connection causes the iSCSI device nodes 103to be destroyed. 104After reconnecting, they will be created again. 105By default, the device nodes are left intact. 106While the connection is down all input/output operations are suspended, to be 107retried after the connection is reestablished. 108.El 109.Sh SEE ALSO 110.Xr iser 4 , 111.Xr iscsi.conf 5 , 112.Xr iscsictl 8 , 113.Xr iscsid 8 114.Sh HISTORY 115The 116.Nm 117subsystem first appeared in 118.Fx 10.0 . 119.Sh AUTHORS 120The 121.Nm 122subsystem was developed by 123.An Edward Tomasz Napierala Aq Mt trasz@FreeBSD.org 124under sponsorship from the FreeBSD Foundation. 125