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.Dd November 15, 2002 29.Dt SCSI_TARGET 8 30.Os 31.Sh NAME 32.Nm scsi_target 33.Nd usermode SCSI disk emulator 34.Sh SYNOPSIS 35.Nm 36.Op Fl AdST 37.Op Fl b Ar size 38.Op Fl c Ar size 39.Op Fl s Ar size 40.Op Fl W Ar num 41.Ar bus : Ns Ar target : Ns Ar lun 42.Ar filename 43.Sh DESCRIPTION 44The 45.Nm 46utility emulates a SCSI target device using the 47.Xr targ 4 48device driver. 49It supports the basic commands of a direct access device, like 50.Xr da 4 . 51In typical operation, it opens a control device and 52enables target mode for the specified LUN. 53It then communicates with 54the SIM using CCBs exchanged via 55.Xr read 2 56and 57.Xr write 2 . 58READ and WRITE CDBs are satisfied with the specified backing store file. 59.Pp 60For performance, all backing store accesses use 61.Xr aio 4 . 62Thus, 63.Nm 64requires a kernel compiled with 65.Cd "options VFS_AIO" . 66.Pp 67Options: 68.Bl -tag -width indent 69.It Fl A 70Enable 16 addresses if supported by the SIM. 71Default is 8. 72.It Fl S 73Enable synchronous transfers if supported by the SIM. 74Default is disabled. 75.It Fl T 76Enable tagged queuing if supported by the SIM. 77Default is no tagged queuing. 78.It Fl W Cm 8 | 16 | 32 79Enable 16 or 32 bit wide transfers if supported by the SIM. 80Default is 8. 81.It Fl b Ar bufsize 82Set buffer size for transfers. 83Transfers larger than this will be split into multiple transfers. 84.It Fl c Ar sectorsize 85Set sector size for emulated volume. 86Default is 512. 87.It Fl d 88Enable debugging output in 89.Nm 90and its associated control device. 91.It Fl s Ar volsize 92Use a different size for the emulated volume. 93Must be less than or equal to the size of 94.Ar filename . 95If the number ends with a 96.Dq Li k , 97.Dq Li m , 98.Dq Li g , 99.Dq Li t , 100.Dq Li p , 101or 102.Dq Li e , 103the number is multiplied by 2^10 (1K), 2^20 (1M), 2^30 (1G), 2^40 (1T), 1042^50 (1P) and 2^60 (1E) 105respectively. 106.El 107.Pp 108Required arguments: 109.Bl -tag -width indent 110.It Ar bus : Ns Ar target : Ns Ar lun 111Attach to specified bus ID, target ID, and LUN. 112.It Ar filename 113File to use as a backing store. 114.El 115.Pp 116All options default to the minimal functionality of SCSI-1. 117To be safe, 118.Nm 119checks the SIM for the requested capability before enabling target mode. 120.Sh FILES 121.Bl -tag -width ".Pa /usr/share/examples/scsi_target" -compact 122.It Pa /dev/targ* 123Control devices. 124.It Pa /usr/share/examples/scsi_target 125Source directory. 126.El 127.Sh EXAMPLES 128Create a 5 megabyte backing store file. 129.Pp 130.Dl "dd if=/dev/zero of=vol size=1m count=5" 131.Pp 132Enable target mode on bus 0, target ID 1, LUN 0, using 133.Pa vol 134as the backing store for READ6/10 and WRITE6/10 commands. 135Only the first 1000 bytes of 136.Pa vol 137will be used. 138Debugging information will be output. 13916-bit wide transfers will be used if the SIM supports them. 140.Pp 141.Dl "scsi_target -d -s 1000 -W 16 0:1:0 vol" 142.Sh SEE ALSO 143.Xr scsi 4 , 144.Xr targ 4 145.Sh AUTHORS 146.An -nosplit 147The 148.Nm 149example first appeared in 150.Fx 3.0 151and was written by 152.An Justin T. Gibbs . 153It was rewritten for 154.Fx 5.0 155by 156.An Nate Lawson Aq Mt nate@root.org . 157