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