| scsi.4 (193204) | scsi.4 (204704) |
|---|---|
| 1.\" Copyright (c) 1996 2.\" Julian Elischer <julian@FreeBSD.org>. 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 unchanged lines hidden (view full) --- 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" | 1.\" Copyright (c) 1996 2.\" Julian Elischer <julian@FreeBSD.org>. 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 unchanged lines hidden (view full) --- 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" |
| 26.\" $FreeBSD: head/share/man/man4/scsi.4 193204 2009-06-01 06:52:03Z jmallett $ 27.Dd October 15, 1998 28.Dt SCSI 4 | 26.\" $FreeBSD: head/share/man/man4/scsi.4 204704 2010-03-04 10:59:21Z mav $ 27.Dd March 4, 2010 28.Dt CAM 4 |
| 29.Os 30.Sh NAME | 29.Os 30.Sh NAME |
| 31.Nm SCSI , | |
| 32.Nm CAM | 31.Nm CAM |
| 33.Nd CAM SCSI subsystem | 32.Nd Common Access Method SCSI/ATA subsystem |
| 34.Sh SYNOPSIS 35.Cd "device scbus" | 33.Sh SYNOPSIS 34.Cd "device scbus" |
| 35.Cd "device ada" |
|
| 36.Cd "device cd" 37.Cd "device ch" 38.Cd "device da" 39.Cd "device pass" 40.Cd "device pt" 41.Cd "device sa" 42.Cd "options CAMDEBUG" 43.Cd "options CAM_DEBUG_BUS=-1" 44.Cd "options CAM_DEBUG_TARGET=-1" 45.Cd "options CAM_DEBUG_LUN=-1" 46.Cd "options CAM_DEBUG_FLAGS=CAM_DEBUG_INFO|CAM_DEBUG_CDB" 47.Cd "options CAM_MAX_HIGHPOWER=4" 48.Cd "options SCSI_NO_SENSE_STRINGS" 49.Cd "options SCSI_NO_OP_STRINGS" 50.Cd "options SCSI_DELAY=8000" 51.Sh DESCRIPTION | 36.Cd "device cd" 37.Cd "device ch" 38.Cd "device da" 39.Cd "device pass" 40.Cd "device pt" 41.Cd "device sa" 42.Cd "options CAMDEBUG" 43.Cd "options CAM_DEBUG_BUS=-1" 44.Cd "options CAM_DEBUG_TARGET=-1" 45.Cd "options CAM_DEBUG_LUN=-1" 46.Cd "options CAM_DEBUG_FLAGS=CAM_DEBUG_INFO|CAM_DEBUG_CDB" 47.Cd "options CAM_MAX_HIGHPOWER=4" 48.Cd "options SCSI_NO_SENSE_STRINGS" 49.Cd "options SCSI_NO_OP_STRINGS" 50.Cd "options SCSI_DELAY=8000" 51.Sh DESCRIPTION |
| 52The CAM 53.Tn SCSI | 52The 53.Nm |
| 54subsystem provides a uniform and modular system for the implementation 55of drivers to control various 56.Tn SCSI | 54subsystem provides a uniform and modular system for the implementation 55of drivers to control various 56.Tn SCSI |
| 57and 58.Tn ATA |
|
| 57devices, and to utilize different 58.Tn SCSI | 59devices, and to utilize different 60.Tn SCSI |
| 61and 62.Tn ATA |
|
| 59host adapters through host adapter drivers. | 63host adapters through host adapter drivers. |
| 60When the system probes the 61.Tn SCSI 62busses, it attaches any devices it finds to the appropriate 63drivers. | 64When the system probes busses, it attaches any devices it finds to the 65appropriate drivers. |
| 64The 65.Xr pass 4 | 66The 67.Xr pass 4 |
| 66driver, if it is configured in the kernel, will attach to all 67.Tn SCSI 68devices. | 68driver, if it is configured in the kernel, will attach to all devices. |
| 69.Sh KERNEL CONFIGURATION 70There are a number of generic kernel configuration options for the | 69.Sh KERNEL CONFIGURATION 70There are a number of generic kernel configuration options for the |
| 71CAM 72.Tn SCSI | 71.Nm |
| 73subsystem: 74.Bl -tag -width SCSI_NO_SENSE_STRINGS 75.It Dv CAMDEBUG | 72subsystem: 73.Bl -tag -width SCSI_NO_SENSE_STRINGS 74.It Dv CAMDEBUG |
| 76This option enables the CAM debugging printf code. | 75This option enables the 76.Nm 77debugging printf code. |
| 77This will not actually 78cause any debugging information to be printed out when included by itself. 79Enabling printouts requires additional configuration. 80See below for details. 81.It Dv "CAM_MAX_HIGHPOWER=4" 82This sets the maximum allowable number of concurrent "high power" commands. 83A "high power" command is a command that takes more electrical power than 84most to complete. | 78This will not actually 79cause any debugging information to be printed out when included by itself. 80Enabling printouts requires additional configuration. 81See below for details. 82.It Dv "CAM_MAX_HIGHPOWER=4" 83This sets the maximum allowable number of concurrent "high power" commands. 84A "high power" command is a command that takes more electrical power than 85most to complete. |
| 85An example of this (and the only command currently 86tagged as "high power") is the | 86An example of this is the |
| 87.Tn SCSI 88START UNIT command. | 87.Tn SCSI 88START UNIT command. |
| 89Starting a SCSI disk often takes significantly more 90electrical power than normal operation of the disk. | 89Starting a disk often takes significantly more electrical power than normal 90operation. |
| 91This option allows the 92user to specify how many concurrent high power commands may be outstanding 93without overloading the power supply on his computer. 94.It Dv SCSI_NO_SENSE_STRINGS 95This eliminates text descriptions of each 96.Tn SCSI 97Additional Sense Code and Additional Sense Code Qualifier pair. 98Since this --- 16 unchanged lines hidden (view full) --- 115Enabling this option for normal use is not recommended, since it slows 116debugging of 117.Tn SCSI 118problems. 119.It Dv SCSI_DELAY=8000 120This is the 121.Tn SCSI 122"bus settle delay." | 91This option allows the 92user to specify how many concurrent high power commands may be outstanding 93without overloading the power supply on his computer. 94.It Dv SCSI_NO_SENSE_STRINGS 95This eliminates text descriptions of each 96.Tn SCSI 97Additional Sense Code and Additional Sense Code Qualifier pair. 98Since this --- 16 unchanged lines hidden (view full) --- 115Enabling this option for normal use is not recommended, since it slows 116debugging of 117.Tn SCSI 118problems. 119.It Dv SCSI_DELAY=8000 120This is the 121.Tn SCSI 122"bus settle delay." |
| 123In CAM, it is specified in | 123In 124.Nm , 125it is specified in |
| 124.Em milliseconds , 125not seconds like the old 126.Tn SCSI 127layer used to do. 128When the kernel boots, it sends a bus reset to each 129.Tn SCSI 130bus to tell each device to reset itself to a default set of transfer 131negotiations and other settings. --- 11 unchanged lines hidden (view full) --- 143One special case is that if the 144.Dv SCSI_DELAY 145is set to 0, that will be taken to mean the "lowest possible value." 146In that case, the 147.Dv SCSI_DELAY 148will be reset to 100ms. 149.El 150.Pp | 126.Em milliseconds , 127not seconds like the old 128.Tn SCSI 129layer used to do. 130When the kernel boots, it sends a bus reset to each 131.Tn SCSI 132bus to tell each device to reset itself to a default set of transfer 133negotiations and other settings. --- 11 unchanged lines hidden (view full) --- 145One special case is that if the 146.Dv SCSI_DELAY 147is set to 0, that will be taken to mean the "lowest possible value." 148In that case, the 149.Dv SCSI_DELAY 150will be reset to 100ms. 151.El 152.Pp |
| 151All devices and the SCSI busses support boot time allocation so that | 153All devices and busses support dynamic allocation so that |
| 152an upper number of devices and controllers does not need to be configured; 153.Cd "device da" 154will suffice for any number of disk drivers. 155.Pp 156The devices are either 157.Em wired 158so they appear as a particular device unit or 159.Em counted --- 39 unchanged lines hidden (view full) --- 199hint.da.0.at="scbus0" 200hint.da.0.target="0" 201hint.da.0.unit="0" 202.Ed 203.Pp 204This assigns 205.Em da0 206to target 0, unit (lun) 0 of scbus 0. | 154an upper number of devices and controllers does not need to be configured; 155.Cd "device da" 156will suffice for any number of disk drivers. 157.Pp 158The devices are either 159.Em wired 160so they appear as a particular device unit or 161.Em counted --- 39 unchanged lines hidden (view full) --- 201hint.da.0.at="scbus0" 202hint.da.0.target="0" 203hint.da.0.unit="0" 204.Ed 205.Pp 206This assigns 207.Em da0 208to target 0, unit (lun) 0 of scbus 0. |
| 207Omitting the target or unit hints will instruct CAM to treat them as wildcards | 209Omitting the target or unit hints will instruct 210.Nm 211to treat them as wildcards |
| 208and use the first respective counted instances. 209These examples can be combined together to allow a peripheral device to be 210wired to any particular controller, bus, target, and/or unit instance. 211.Pp 212When you have a mixture of wired down and counted devices then the 213counting begins with the first non-wired down unit for a particular 214type. 215That is, if you have a disk wired down as 216.Em "device da1" , 217then the first non-wired disk shall come on line as 218.Em da2 . 219.Sh ADAPTERS 220The system allows common device drivers to work through many different 221types of adapters. 222The adapters take requests from the upper layers and do 223all IO between the | 212and use the first respective counted instances. 213These examples can be combined together to allow a peripheral device to be 214wired to any particular controller, bus, target, and/or unit instance. 215.Pp 216When you have a mixture of wired down and counted devices then the 217counting begins with the first non-wired down unit for a particular 218type. 219That is, if you have a disk wired down as 220.Em "device da1" , 221then the first non-wired disk shall come on line as 222.Em da2 . 223.Sh ADAPTERS 224The system allows common device drivers to work through many different 225types of adapters. 226The adapters take requests from the upper layers and do 227all IO between the |
| 224.Em SCSI | 228.Tn SCSI 229or 230.Tn ATA |
| 225bus and the system. 226The maximum size of a transfer is governed by the 227adapter. 228Most adapters can transfer 64KB in a single operation, however 229many can transfer larger amounts. 230.Sh TARGET MODE 231Some adapters support 232.Em target mode 233in which the system is capable of operating as a device, responding to 234operations initiated by another system. 235Target mode is supported for | 231bus and the system. 232The maximum size of a transfer is governed by the 233adapter. 234Most adapters can transfer 64KB in a single operation, however 235many can transfer larger amounts. 236.Sh TARGET MODE 237Some adapters support 238.Em target mode 239in which the system is capable of operating as a device, responding to 240operations initiated by another system. 241Target mode is supported for |
| 236some adapters, but is not yet complete for this version of the CAM | 242some adapters, but is not yet complete for this version of the 243.Nm |
| 237.Tn SCSI 238subsystem. 239.Sh FILES 240see other 241.Nm 242device entries. 243.Sh DIAGNOSTICS 244When the kernel is compiled with options CAMDEBUG, an XPT_DEBUG CCB can be --- 28 unchanged lines hidden (view full) --- 273level, so it is not especially useful. 274The most useful debugging flag is the 275.Dv CAM_DEBUG_CDB 276flag. 277Users can enable debugging from their kernel config file, by using 278the following kernel config options: 279.Bl -tag -width CAM_DEBUG_TARGET 280.It Dv CAMDEBUG | 244.Tn SCSI 245subsystem. 246.Sh FILES 247see other 248.Nm 249device entries. 250.Sh DIAGNOSTICS 251When the kernel is compiled with options CAMDEBUG, an XPT_DEBUG CCB can be --- 28 unchanged lines hidden (view full) --- 280level, so it is not especially useful. 281The most useful debugging flag is the 282.Dv CAM_DEBUG_CDB 283flag. 284Users can enable debugging from their kernel config file, by using 285the following kernel config options: 286.Bl -tag -width CAM_DEBUG_TARGET 287.It Dv CAMDEBUG |
| 281This enables CAM debugging. | 288This enables 289.Nm 290debugging. |
| 282Without this option, users will not even be able 283to turn on debugging from userland via 284.Xr camcontrol 8 . 285.It Dv CAM_DEBUG_FLAGS 286This allows the user to set the various debugging flags described above 287in a kernel config file. 288Flags may be ORed together if the user wishes to 289see printfs for multiple debugging levels. --- 18 unchanged lines hidden (view full) --- 308.Dv CAMDEBUG 309option is their config file, by using the 310.Xr camcontrol 8 311utility. 312See 313.Xr camcontrol 8 314for details. 315.Sh SEE ALSO | 291Without this option, users will not even be able 292to turn on debugging from userland via 293.Xr camcontrol 8 . 294.It Dv CAM_DEBUG_FLAGS 295This allows the user to set the various debugging flags described above 296in a kernel config file. 297Flags may be ORed together if the user wishes to 298see printfs for multiple debugging levels. --- 18 unchanged lines hidden (view full) --- 317.Dv CAMDEBUG 318option is their config file, by using the 319.Xr camcontrol 8 320utility. 321See 322.Xr camcontrol 8 323for details. 324.Sh SEE ALSO |
| 325.Xr ada 4 , |
|
| 316.Xr aha 4 , 317.Xr ahb 4 , 318.Xr ahc 4 , | 326.Xr aha 4 , 327.Xr ahb 4 , 328.Xr ahc 4 , |
| 329.Xr ahci 4 , 330.Xr ata 4 , |
|
| 319.Xr bt 4 , 320.Xr cd 4 , 321.Xr ch 4 , 322.Xr da 4 , 323.Xr pass 4 , 324.Xr pt 4 , 325.Xr sa 4 , 326.Xr xpt 4 , 327.Xr camcontrol 8 328.Sh HISTORY | 331.Xr bt 4 , 332.Xr cd 4 , 333.Xr ch 4 , 334.Xr da 4 , 335.Xr pass 4 , 336.Xr pt 4 , 337.Xr sa 4 , 338.Xr xpt 4 , 339.Xr camcontrol 8 340.Sh HISTORY |
| 329The CAM | 341The 342.Nm |
| 330.Tn SCSI 331subsystem first appeared in 332.Fx 3.0 . | 343.Tn SCSI 344subsystem first appeared in 345.Fx 3.0 . |
| 346The 347.Nm 348ATA support was added in 349.Fx 8.0 . |
|
| 333.Sh AUTHORS 334.An -nosplit | 350.Sh AUTHORS 351.An -nosplit |
| 335The CAM | 352The 353.Nm |
| 336.Tn SCSI 337subsystem was written by 338.An Justin Gibbs 339and 340.An Kenneth Merry . | 354.Tn SCSI 355subsystem was written by 356.An Justin Gibbs 357and 358.An Kenneth Merry . |
| 359The 360.Nm 361.Tn ATA 362support was added by 363.An Alexander Motin Aq mav@FreeBSD.org . |
|