1.\" Copyright (c) 2002 2.\" Nate Lawson. 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.\" 3. Neither the name of the author nor the names of any co-contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY Nate Lawson AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" $FreeBSD: src/share/examples/scsi_target/scsi_target.8,v 1.2.4.1 2003/02/18 22:07:10 njl Exp $ 29.\" $DragonFly: src/share/examples/scsi_target/scsi_target.8,v 1.3 2006/02/17 19:37:09 swildner Exp $ 30.\" 31.Dd November 15, 2002 32.Dt SCSI_TARGET 8 33.Os 34.Sh NAME 35.Nm scsi_target 36.Nd usermode SCSI disk emulator 37.Sh SYNOPSIS 38.Nm 39.Op Fl AdST 40.Op Fl b Ar size 41.Op Fl c Ar size 42.Op Fl s Ar size 43.Op Fl W Ar num 44.Ar bus : Ns Ar target : Ns Ar lun 45.Ar filename 46.Sh DESCRIPTION 47The 48.Nm 49utility emulates a SCSI target device using the 50.Xr targ 4 51device driver. 52It supports the basic commands of a direct access device, like 53.Xr da 4 . 54In typical operation, it opens a control device and 55enables target mode for the specified LUN. 56It then communicates with 57the SIM using CCBs exchanged via 58.Xr read 2 59and 60.Xr write 2 . 61READ and WRITE CDBs are satisfied with the specified backing store file. 62.Pp 63For performance, all backing store accesses use 64.Xr aio 4 . 65Thus, 66.Nm 67requires a kernel compiled with 68.Cd "options VFS_AIO" . 69.Pp 70Options: 71.Bl -tag -width indent 72.It Fl A 73Enable 16 addresses if supported by the SIM. 74Default is 8. 75.It Fl S 76Enable synchronous transfers if supported by the SIM. 77Default is disabled. 78.It Fl T 79Enable tagged queuing if supported by the SIM. 80Default is no tagged queuing. 81.It Fl W Cm 8 | 16 | 32 82Enable 16 or 32 bit wide transfers if supported by the SIM. 83Default is 8. 84.It Fl b Ar bufsize 85Set buffer size for transfers. 86Transfers larger than this will be split into multiple transfers. 87.It Fl c Ar sectorsize 88Set sector size for emulated volume. 89Default is 512. 90.It Fl d 91Enable debugging output in 92.Nm 93and its associated control device. 94.It Fl s Ar volsize 95Use a different size for the emulated volume. 96Must be less than or equal to the size of 97.Ar filename . 98.El 99.Pp 100Required arguments: 101.Bl -tag -width indent 102.It Ar bus : Ns Ar target : Ns Ar lun 103Attach to specified bus ID, target ID, and LUN. 104.It Ar filename 105File to use as a backing store. 106.El 107.Pp 108All options default to the minimal functionality of SCSI-1. 109To be safe, 110.Nm 111checks the SIM for the requested capability before enabling target mode. 112.Sh FILES 113.Bl -tag -width ".Pa /usr/share/examples/scsi_target" -compact 114.It Pa /dev/targ* 115Control devices. 116.It Pa /usr/share/examples/scsi_target 117Source directory. 118.El 119.Sh EXAMPLES 120Create a 5 megabyte backing store file. 121.Pp 122.Dl "dd if=/dev/zero of=vol size=1m count=5" 123.Pp 124Enable target mode on bus 0, target ID 1, LUN 0, using 125.Pa vol 126as the backing store for READ6/10 and WRITE6/10 commands. 127Only the first 1000 bytes of 128.Pa vol 129will be used. 130Debugging information will be output. 13116-bit wide transfers will be used if the SIM supports them. 132.Pp 133.Dl "scsi_target -d -v 1000 -W 16 0:1:0 vol" 134.Sh SEE ALSO 135.Xr scsi 4 , 136.Xr targ 4 137.Sh AUTHORS 138.An -nosplit 139The 140.Nm 141example first appeared in 142.Fx 3.0 143and was written by 144.An Justin T. Gibbs . 145It was rewritten for 146.Fx 5.0 147by 148.An Nate Lawson Aq nate@root.org . 149