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fea681da | 1 | .\" Copyright 1995 Robert K. Nichols (Robert.K.Nichols@att.com) |
e2af0daf | 2 | .\" Copyright 1999-2005 Kai Mäkisara (Kai.Makisara@kolumbus.fi) |
fea681da | 3 | .\" |
93015253 | 4 | .\" %%%LICENSE_START(VERBATIM) |
fea681da MK |
5 | .\" Permission is granted to make and distribute verbatim copies of this |
6 | .\" manual provided the copyright notice and this permission notice are | |
7 | .\" preserved on all copies. | |
8 | .\" | |
9 | .\" Permission is granted to copy and distribute modified versions of this | |
10 | .\" manual under the conditions for verbatim copying, provided that the | |
11 | .\" entire resulting derived work is distributed under the terms of a | |
12 | .\" permission notice identical to this one. | |
e2af0daf | 13 | .\" |
fea681da MK |
14 | .\" Since the Linux kernel and libraries are constantly changing, this |
15 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
16 | .\" responsibility for errors or omissions, or for damages resulting from | |
17 | .\" the use of the information contained herein. The author(s) may not | |
18 | .\" have taken the same level of care in the production of this manual, | |
19 | .\" which is licensed free of charge, as they might when working | |
20 | .\" professionally. | |
e2af0daf | 21 | .\" |
fea681da MK |
22 | .\" Formatted or processed versions of this manual, if unaccompanied by |
23 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 24 | .\" %%%LICENSE_END |
9ba01802 | 25 | .TH ST 4 2019-03-06 "Linux" "Linux Programmer's Manual" |
fea681da MK |
26 | .SH NAME |
27 | st \- SCSI tape device | |
28 | .SH SYNOPSIS | |
29 | .nf | |
30 | .B #include <sys/mtio.h> | |
68e4db0a | 31 | .PP |
fea681da | 32 | .BI "int ioctl(int " fd ", int " request " [, (void *)" arg3 "]);" |
e40c76c0 MK |
33 | .BI "int ioctl(int " fd ", MTIOCTOP, (struct mtop *)" mt_cmd ); |
34 | .BI "int ioctl(int " fd ", MTIOCGET, (struct mtget *)" mt_status ); | |
35 | .BI "int ioctl(int " fd ", MTIOCPOS, (struct mtpos *)" mt_pos ); | |
fea681da MK |
36 | .fi |
37 | .SH DESCRIPTION | |
38 | The | |
39 | .B st | |
40 | driver provides the interface to a variety of SCSI tape devices. | |
41 | Currently, the driver takes control of all detected devices of type | |
cba04495 | 42 | \(lqsequential-access\(rq. |
fea681da MK |
43 | The |
44 | .B st | |
45 | driver uses major device number 9. | |
46 | .PP | |
c13182ef MK |
47 | Each device uses eight minor device numbers. |
48 | The lowermost five bits | |
fea681da | 49 | in the minor numbers are assigned sequentially in the order of |
c13182ef MK |
50 | detection. |
51 | In the 2.6 kernel, the bits above the eight lowermost bits are | |
e51d6af5 | 52 | concatenated to the five lowermost bits to form the tape number. |
e2af0daf | 53 | The minor numbers can be grouped into |
fea681da MK |
54 | two sets of four numbers: the principal (auto-rewind) minor device numbers, |
55 | .IR n , | |
e2af0daf | 56 | and the \(lqno-rewind\(rq device numbers, |
cba04495 | 57 | .RI ( n " + 128)." |
fea681da | 58 | Devices opened using the principal device number will be sent a |
e40c76c0 MK |
59 | .BR REWIND |
60 | command when they are closed. | |
fea681da MK |
61 | Devices opened using the \(lqno-rewind\(rq device number will not. |
62 | (Note that using an auto-rewind device for positioning the tape with, | |
63 | for instance, mt does not lead to the desired result: the tape is | |
64 | rewound after the mt command and the next command starts from the | |
65 | beginning of the tape). | |
66 | .PP | |
67 | Within each group, four minor numbers are available to define | |
68 | devices with different characteristics (block size, compression, | |
c13182ef MK |
69 | density, etc.) |
70 | When the system starts up, only the first device is available. | |
71 | The other three are activated when the default | |
6387216b MK |
72 | characteristics are defined (see below). |
73 | (By changing compile-time | |
fea681da MK |
74 | constants, it is possible to change the balance between the maximum |
75 | number of tape drives and the number of minor numbers for each | |
c13182ef MK |
76 | drive. |
77 | The default allocation allows control of 32 tape drives. | |
fea681da MK |
78 | For instance, it is possible to control up to 64 tape drives |
79 | with two minor numbers for different options.) | |
80 | .PP | |
81 | Devices are typically created by: | |
e646a1ba | 82 | .PP |
a6e2f128 | 83 | .in +4n |
e646a1ba | 84 | .EX |
2bc2f479 MK |
85 | mknod \-m 666 /dev/st0 c 9 0 |
86 | mknod \-m 666 /dev/st0l c 9 32 | |
87 | mknod \-m 666 /dev/st0m c 9 64 | |
88 | mknod \-m 666 /dev/st0a c 9 96 | |
89 | mknod \-m 666 /dev/nst0 c 9 128 | |
90 | mknod \-m 666 /dev/nst0l c 9 160 | |
91 | mknod \-m 666 /dev/nst0m c 9 192 | |
92 | mknod \-m 666 /dev/nst0a c 9 224 | |
b8302363 | 93 | .EE |
a6e2f128 | 94 | .in |
fea681da MK |
95 | .PP |
96 | There is no corresponding block device. | |
97 | .PP | |
98 | The driver uses an internal buffer that has to be large enough to hold | |
c13182ef MK |
99 | at least one tape block. |
100 | In kernels before 2.1.121, the buffer is | |
101 | allocated as one contiguous block. | |
102 | This limits the block size to the | |
fea681da | 103 | largest contiguous block of memory the kernel allocator can provide. |
c4b7e5ac MK |
104 | The limit is currently 128\ kB for 32-bit architectures and |
105 | 256\ kB for 64-bit architectures. | |
c13182ef MK |
106 | In newer kernels the driver |
107 | allocates the buffer in several parts if necessary. | |
108 | By default, the | |
109 | maximum number of parts is 16. | |
110 | This means that the maximum block size | |
c4b7e5ac | 111 | is very large (2\ MB if allocation of 16 blocks of 128\ kB succeeds). |
fea681da MK |
112 | .PP |
113 | The driver's internal buffer size is determined by a compile-time | |
114 | constant which can be overridden with a kernel startup option. | |
115 | In addition to this, the driver tries to allocate a larger temporary | |
cf50118f | 116 | buffer at run time if necessary. |
c13182ef | 117 | However, run-time allocation of large |
fea681da MK |
118 | contiguous blocks of memory may fail and it is advisable not to rely |
119 | too much on dynamic buffer allocation with kernels older than 2.1.121 | |
120 | (this applies also to demand-loading the driver with kerneld or kmod). | |
121 | .PP | |
122 | The driver does not specifically support any tape drive brand or | |
c13182ef MK |
123 | model. |
124 | After system start-up the tape device options are defined by | |
e2af0daf MK |
125 | the drive firmware. |
126 | For example, if the drive firmware selects fixed-block mode, | |
c13182ef MK |
127 | the tape device uses fixed-block mode. |
128 | The options can | |
fea681da | 129 | be changed with explicit |
5e21af3a | 130 | .BR ioctl (2) |
fea681da | 131 | calls and remain in effect when the device is closed and reopened. |
24b74457 | 132 | Setting the options affects both the auto-rewind and the nonrewind |
fea681da MK |
133 | device. |
134 | .PP | |
135 | Different options can be specified for the different devices within | |
c13182ef MK |
136 | the subgroup of four. |
137 | The options take effect when the device is | |
138 | opened. | |
139 | For example, the system administrator can define | |
e2af0daf MK |
140 | one device that writes in fixed-block mode with a certain block size, |
141 | and one which writes in variable-block mode (if the drive supports | |
fea681da MK |
142 | both modes). |
143 | .PP | |
144 | The driver supports | |
145 | .B tape partitions | |
c13182ef MK |
146 | if they are supported by the drive. |
147 | (Note that the tape partitions | |
148 | have nothing to do with disk partitions. | |
149 | A partitioned tape can be | |
150 | seen as several logical tapes within one medium.) | |
151 | Partition support has to be enabled with an | |
5e21af3a | 152 | .BR ioctl (2). |
1e321034 | 153 | The tape |
fea681da MK |
154 | location is preserved within each partition across partition changes. |
155 | The partition used for subsequent tape operations is | |
c13182ef | 156 | selected with an |
5e21af3a | 157 | .BR ioctl (2). |
1e321034 | 158 | The partition switch is executed together with |
fea681da | 159 | the next tape operation in order to avoid unnecessary tape |
c13182ef MK |
160 | movement. |
161 | The maximum number of partitions on a tape is defined by a | |
162 | compile-time constant (originally four). | |
163 | The driver contains an | |
5e21af3a | 164 | .BR ioctl (2) |
1e321034 | 165 | that can format a tape with either one or two partitions. |
fea681da MK |
166 | .PP |
167 | Device | |
8478ee02 | 168 | .I /dev/tape |
fea681da MK |
169 | is usually created as a hard or soft link to the default tape device |
170 | on the system. | |
e2af0daf MK |
171 | .PP |
172 | Starting from kernel 2.6.2, the driver exports in the sysfs directory | |
0daa9e92 | 173 | .I /sys/class/scsi_tape |
e2af0daf | 174 | the attached devices and some parameters assigned to the devices. |
73d8cece | 175 | .SS Data transfer |
e2af0daf MK |
176 | The driver supports operation in both fixed-block mode and |
177 | variable-block mode (if supported by the drive). | |
178 | In fixed-block mode the drive | |
fea681da | 179 | writes blocks of the specified size and the block size is not |
e2af0daf MK |
180 | dependent on the byte counts of the write system calls. |
181 | In variable-block mode one tape block is written for each write call | |
182 | and the byte | |
c13182ef MK |
183 | count determines the size of the corresponding tape block. |
184 | Note that | |
e2af0daf | 185 | the blocks on the tape don't contain any information about the |
fea681da MK |
186 | writing mode: when reading, the only important thing is to use |
187 | commands that accept the block sizes on the tape. | |
188 | .PP | |
e2af0daf | 189 | In variable-block mode the read byte count does not have to match |
c13182ef MK |
190 | the tape block size exactly. |
191 | If the byte count is larger than the | |
fea681da | 192 | next block on tape, the driver returns the data and the function |
c13182ef MK |
193 | returns the actual block size. |
194 | If the block size is larger than the | |
9787e2b6 | 195 | byte count, an error is returned. |
fea681da | 196 | .PP |
e2af0daf | 197 | In fixed-block mode the read byte counts can be arbitrary if |
fea681da | 198 | buffering is enabled, or a multiple of the tape block size if |
c13182ef MK |
199 | buffering is disabled. |
200 | Kernels before 2.1.121 allow writes with | |
201 | arbitrary byte count if buffering is enabled. | |
202 | In all other cases | |
fea681da MK |
203 | (kernel before 2.1.121 with buffering disabled or newer kernel) the |
204 | write byte count must be a multiple of the tape block size. | |
205 | .PP | |
e2af0daf | 206 | In the 2.6 kernel, the driver tries to use direct transfers between the user |
c13182ef MK |
207 | buffer and the device. |
208 | If this is not possible, the driver's internal buffer | |
209 | is used. | |
210 | The reasons for not using direct transfers include improper alignment | |
e2af0daf | 211 | of the user buffer (default is 512 bytes but this can be changed by the HBA |
90500431 | 212 | driver), one or more pages of the user buffer not reachable by the |
f78ed33a | 213 | SCSI adapter, and so on. |
e2af0daf | 214 | .PP |
fea681da MK |
215 | A filemark is automatically written to tape if the last tape operation |
216 | before close was a write. | |
217 | .PP | |
218 | When a filemark is encountered while reading, the following | |
c13182ef MK |
219 | happens. |
220 | If there are data remaining in the buffer when the filemark | |
221 | is found, the buffered data is returned. | |
222 | The next read returns zero | |
223 | bytes. | |
224 | The following read returns data from the next file. | |
225 | The end of | |
fea681da | 226 | recorded data is signaled by returning zero bytes for two consecutive |
c13182ef MK |
227 | read calls. |
228 | The third read returns an error. | |
2b2581ee | 229 | .SS Ioctls |
c13182ef | 230 | The driver supports three |
5e21af3a | 231 | .BR ioctl (2) |
1e321034 | 232 | requests. |
fea681da MK |
233 | Requests not recognized by the |
234 | .B st | |
235 | driver are passed to the | |
236 | .B SCSI | |
237 | driver. | |
238 | The definitions below are from | |
8478ee02 | 239 | .IR /usr/include/linux/mtio.h : |
73d8cece | 240 | .SS MTIOCTOP \(em perform a tape operation |
fea681da MK |
241 | .PP |
242 | This request takes an argument of type | |
5049da5b | 243 | .IR "(struct mtop\ *)" . |
fea681da | 244 | Not all drives support all operations. |
a9b4ebbc MK |
245 | The driver returns an |
246 | .B EIO | |
247 | error if the drive rejects an operation. | |
fea681da | 248 | .PP |
088a639b | 249 | .in +4n |
b8302363 | 250 | .EX |
e40c76c0 | 251 | /* Structure for MTIOCTOP \- mag tape op command: */ |
fea681da | 252 | struct mtop { |
cf0a9ace MK |
253 | short mt_op; /* operations defined below */ |
254 | int mt_count; /* how many of them */ | |
fea681da | 255 | }; |
b8302363 | 256 | .EE |
e40c76c0 | 257 | .in |
fea681da MK |
258 | .PP |
259 | Magnetic Tape operations for normal tape use: | |
e40c76c0 | 260 | .TP 14 |
e40c76c0 | 261 | .B MTBSF |
fea681da | 262 | Backward space over |
f19a0f03 | 263 | .I mt_count |
fea681da | 264 | filemarks. |
e40c76c0 MK |
265 | .TP |
266 | .B MTBSFM | |
fea681da | 267 | Backward space over |
f19a0f03 | 268 | .I mt_count |
fea681da MK |
269 | filemarks. |
270 | Reposition the tape to the EOT side of the last filemark. | |
e40c76c0 MK |
271 | .TP |
272 | .B MTBSR | |
fea681da | 273 | Backward space over |
f19a0f03 | 274 | .I mt_count |
fea681da | 275 | records (tape blocks). |
e40c76c0 MK |
276 | .TP |
277 | .B MTBSS | |
fea681da | 278 | Backward space over |
f19a0f03 | 279 | .I mt_count |
fea681da | 280 | setmarks. |
e40c76c0 MK |
281 | .TP |
282 | .B MTCOMPRESSION | |
fea681da | 283 | Enable compression of tape data within the drive if |
f19a0f03 | 284 | .I mt_count |
c7094399 | 285 | is nonzero and disable compression if |
f19a0f03 | 286 | .I mt_count |
c13182ef MK |
287 | is zero. |
288 | This command uses the MODE page 15 supported by most DATs. | |
e40c76c0 MK |
289 | .TP |
290 | .B MTEOM | |
fea681da | 291 | Go to the end of the recorded media (for appending files). |
e40c76c0 MK |
292 | .TP |
293 | .B MTERASE | |
c13182ef MK |
294 | Erase tape. |
295 | With 2.6 kernel, short erase (mark tape empty) is performed if the | |
296 | argument is zero. | |
2b9b829d | 297 | Otherwise, long erase (erase all) is done. |
e40c76c0 MK |
298 | .TP |
299 | .B MTFSF | |
fea681da | 300 | Forward space over |
f19a0f03 | 301 | .I mt_count |
fea681da | 302 | filemarks. |
e40c76c0 MK |
303 | .TP |
304 | .B MTFSFM | |
fea681da | 305 | Forward space over |
f19a0f03 | 306 | .I mt_count |
fea681da MK |
307 | filemarks. |
308 | Reposition the tape to the BOT side of the last filemark. | |
e40c76c0 MK |
309 | .TP |
310 | .B MTFSR | |
fea681da | 311 | Forward space over |
f19a0f03 | 312 | .I mt_count |
fea681da | 313 | records (tape blocks). |
e40c76c0 MK |
314 | .TP |
315 | .B MTFSS | |
fea681da | 316 | Forward space over |
f19a0f03 | 317 | .I mt_count |
fea681da | 318 | setmarks. |
e40c76c0 MK |
319 | .TP |
320 | .B MTLOAD | |
c13182ef MK |
321 | Execute the SCSI load command. |
322 | A special case is available for some HP | |
323 | autoloaders. | |
324 | If | |
f19a0f03 | 325 | .I mt_count |
08362d55 MK |
326 | is the constant |
327 | .B MT_ST_HPLOADER_OFFSET | |
328 | plus a number, the number is | |
fea681da | 329 | sent to the drive to control the autoloader. |
e40c76c0 MK |
330 | .TP |
331 | .B MTLOCK | |
fea681da | 332 | Lock the tape drive door. |
e40c76c0 MK |
333 | .TP |
334 | .B MTMKPART | |
c13182ef MK |
335 | Format the tape into one or two partitions. |
336 | If | |
f19a0f03 | 337 | .I mt_count |
8661af11 | 338 | is positive, it gives the size of partition 1 and partition |
401117dc MK |
339 | 0 contains the rest of the tape. |
340 | If | |
f19a0f03 | 341 | .I mt_count |
fea681da | 342 | is zero, the tape is formatted into one partition. |
9787e2b6 MK |
343 | From kernel version 4.6, |
344 | .\" commit 8038e6456a3e6f5c4759e0d73c4f9165b90c93e7 | |
345 | a negative | |
8661af11 | 346 | .I mt_count |
401117dc MK |
347 | specifies the size of partition 0 and |
348 | the rest of the tape contains partition 1. | |
349 | The physical ordering of partitions depends on the drive. | |
fea681da | 350 | This command is not allowed for a drive unless the partition support |
e40c76c0 MK |
351 | is enabled for the drive (see |
352 | .BR MT_ST_CAN_PARTITIONS | |
353 | below). | |
354 | .TP | |
355 | .B MTNOP | |
5503c85e | 356 | No op\(emflushes the driver's buffer as a side effect. |
979c2c91 | 357 | Should be used before reading status with |
e40c76c0 MK |
358 | .BR MTIOCGET . |
359 | .TP | |
360 | .B MTOFFL | |
fea681da | 361 | Rewind and put the drive off line. |
e40c76c0 MK |
362 | .TP |
363 | .B MTRESET | |
fea681da | 364 | Reset drive. |
e40c76c0 MK |
365 | .TP |
366 | .B MTRETEN | |
3f1c1b0a | 367 | Re-tension tape. |
e40c76c0 MK |
368 | .TP |
369 | .B MTREW | |
fea681da | 370 | Rewind. |
e40c76c0 MK |
371 | .TP |
372 | .B MTSEEK | |
fea681da | 373 | Seek to the tape block number specified in |
f19a0f03 | 374 | .IR mt_count . |
e40c76c0 MK |
375 | This operation requires either a SCSI-2 drive that supports the |
376 | .B LOCATE | |
fea681da MK |
377 | command (device-specific address) |
378 | or a Tandberg-compatible SCSI-1 drive (Tandberg, Archive | |
e40c76c0 | 379 | Viper, Wangtek, ...). |
fea681da | 380 | The block number should be one that was previously returned by |
e40c76c0 MK |
381 | .BR MTIOCPOS |
382 | if device-specific addresses are used. | |
383 | .TP | |
384 | .B MTSETBLK | |
fea681da | 385 | Set the drive's block length to the value specified in |
f19a0f03 | 386 | .IR mt_count . |
fea681da | 387 | A block length of zero sets the drive to variable block size mode. |
e40c76c0 MK |
388 | .TP |
389 | .B MTSETDENSITY | |
fea681da | 390 | Set the tape density to the code in |
f19a0f03 | 391 | .IR mt_count . |
fea681da MK |
392 | The density codes supported by a drive can be found from the drive |
393 | documentation. | |
e40c76c0 MK |
394 | .TP |
395 | .B MTSETPART | |
fea681da | 396 | The active partition is switched to |
f19a0f03 | 397 | .IR mt_count . |
c13182ef MK |
398 | The partitions are numbered from zero. |
399 | This command is not allowed for | |
fea681da | 400 | a drive unless the partition support is enabled for the drive (see |
e40c76c0 MK |
401 | .B MT_ST_CAN_PARTITIONS |
402 | below). | |
403 | .TP | |
404 | .B MTUNLOAD | |
fea681da | 405 | Execute the SCSI unload command (does not eject the tape). |
e40c76c0 MK |
406 | .TP |
407 | .B MTUNLOCK | |
fea681da | 408 | Unlock the tape drive door. |
e40c76c0 MK |
409 | .TP |
410 | .B MTWEOF | |
e2af0daf | 411 | Write |
f19a0f03 | 412 | .I mt_count |
fea681da | 413 | filemarks. |
e40c76c0 MK |
414 | .TP |
415 | .B MTWSM | |
fea681da | 416 | Write |
f19a0f03 | 417 | .I mt_count |
fea681da | 418 | setmarks. |
fea681da MK |
419 | .PP |
420 | Magnetic Tape operations for setting of device options (by the superuser): | |
e40c76c0 MK |
421 | .TP 8 |
422 | .B MTSETDRVBUFFER | |
fea681da | 423 | Set various drive and driver options according to bits encoded in |
f19a0f03 | 424 | .IR mt_count . |
e2af0daf | 425 | These consist of the drive's buffering mode, a set of Boolean driver |
fea681da | 426 | options, the buffer write threshold, defaults for the block size and |
74aace8a | 427 | density, and timeouts (only in kernels 2.1 and later). |
fea681da MK |
428 | A single operation can affect only one item in the list above (the |
429 | Booleans counted as one item.) | |
fea681da MK |
430 | .IP |
431 | A value having zeros in the high-order 4 bits will be used to set the | |
432 | drive's buffering mode. | |
433 | The buffering modes are: | |
434 | .RS 12 | |
435 | .IP 0 4 | |
979c2c91 | 436 | The drive will not report |
e40c76c0 MK |
437 | .BR GOOD |
438 | status on write commands until the data | |
fea681da | 439 | blocks are actually written to the medium. |
fea681da | 440 | .IP 1 |
979c2c91 | 441 | The drive may report |
e40c76c0 MK |
442 | .BR GOOD |
443 | status on write commands as soon as all the | |
fea681da MK |
444 | data has been transferred to the drive's internal buffer. |
445 | .IP 2 | |
979c2c91 | 446 | The drive may report |
e40c76c0 MK |
447 | .BR GOOD |
448 | status on write commands as soon as (a) all | |
fea681da MK |
449 | the data has been transferred to the drive's internal buffer, and |
450 | (b) all buffered data from different initiators has been successfully | |
451 | written to the medium. | |
fea681da | 452 | .RE |
e40c76c0 | 453 | .IP |
fea681da | 454 | To control the write threshold the value in |
f19a0f03 | 455 | .I mt_count |
fea681da | 456 | must include the constant |
e40c76c0 | 457 | .BR MT_ST_WRITE_THRESHOLD |
87f6d861 | 458 | bitwise ORed with a block count in the low 28 bits. |
fea681da MK |
459 | The block count refers to 1024-byte blocks, not the physical block |
460 | size on the tape. | |
461 | The threshold cannot exceed the driver's internal buffer size (see | |
e40c76c0 | 462 | DESCRIPTION, above). |
fea681da MK |
463 | .IP |
464 | To set and clear the Boolean options | |
465 | the value in | |
f19a0f03 | 466 | .I mt_count |
e40c76c0 MK |
467 | must include one of the constants |
468 | .BR MT_ST_BOOLEANS , | |
979c2c91 | 469 | .BR MT_ST_SETBOOLEANS , |
e40c76c0 MK |
470 | .BR MT_ST_CLEARBOOLEANS , |
471 | or | |
472 | .BR MT_ST_DEFBOOLEANS | |
87f6d861 | 473 | bitwise ORed with |
fea681da | 474 | whatever combination of the following options is desired. |
e40c76c0 MK |
475 | Using |
476 | .BR MT_ST_BOOLEANS | |
477 | the options can be set to the values | |
c13182ef | 478 | defined in the corresponding bits. |
e40c76c0 MK |
479 | With |
480 | .BR MT_ST_SETBOOLEANS | |
979c2c91 | 481 | the options can be selectively set and with |
e40c76c0 | 482 | .BR MT_ST_DEFBOOLEANS |
fea681da MK |
483 | selectively cleared. |
484 | .IP "" | |
485 | The default options for a tape device are set with | |
e40c76c0 | 486 | .BR MT_ST_DEFBOOLEANS . |
24b74457 | 487 | A nonactive tape device (e.g., device with |
fea681da | 488 | minor 32 or 160) is activated when the default options for it are |
c13182ef MK |
489 | defined the first time. |
490 | An activated device inherits from the device | |
fea681da MK |
491 | activated at start-up the options not set explicitly. |
492 | .IP "" | |
493 | The Boolean options are: | |
fea681da | 494 | .RS |
979c2c91 | 495 | .TP |
e40c76c0 | 496 | .BR MT_ST_BUFFER_WRITES " (Default: true)" |
e2af0daf | 497 | Buffer all write operations in fixed-block mode. |
fea681da MK |
498 | If this option is false and the drive uses a fixed block size, then |
499 | all write operations must be for a multiple of the block size. | |
ae03dc66 | 500 | This option must be set false to write reliable multivolume archives. |
ddf54565 | 501 | .TP |
e40c76c0 | 502 | .BR MT_ST_ASYNC_WRITES " (Default: true)" |
e2af0daf | 503 | When this option is true, write operations return immediately without |
fea681da MK |
504 | waiting for the data to be transferred to the drive if the data fits |
505 | into the driver's buffer. | |
506 | The write threshold determines how full the buffer must be before a | |
507 | new SCSI write command is issued. | |
508 | Any errors reported by the drive will be held until the next | |
509 | operation. | |
ae03dc66 | 510 | This option must be set false to write reliable multivolume archives. |
e40c76c0 MK |
511 | .TP |
512 | .BR MT_ST_READ_AHEAD " (Default: true)" | |
fea681da | 513 | This option causes the driver to provide read buffering and |
e2af0daf | 514 | read-ahead in fixed-block mode. |
fea681da MK |
515 | If this option is false and the drive uses a fixed block size, then |
516 | all read operations must be for a multiple of the block size. | |
e40c76c0 MK |
517 | .TP |
518 | .BR MT_ST_TWO_FM " (Default: false)" | |
fea681da MK |
519 | This option modifies the driver behavior when a file is closed. |
520 | The normal action is to write a single filemark. | |
c3235368 | 521 | If the option is true, the driver will write two filemarks and |
fea681da | 522 | backspace over the second one. |
fea681da MK |
523 | .IP |
524 | Note: | |
525 | This option should not be set true for QIC tape drives since they are | |
526 | unable to overwrite a filemark. | |
527 | These drives detect the end of recorded data by testing for blank tape | |
c13182ef MK |
528 | rather than two consecutive filemarks. |
529 | Most other current drives also | |
fea681da MK |
530 | detect the end of recorded data and using two filemarks is usually |
531 | necessary only when interchanging tapes with some other systems. | |
e40c76c0 MK |
532 | .TP |
533 | .BR MT_ST_DEBUGGING " (Default: false)" | |
fea681da | 534 | This option turns on various debugging messages from the driver |
e40c76c0 MK |
535 | (effective only if the driver was compiled with |
536 | .B DEBUG | |
c7094399 | 537 | defined nonzero). |
e40c76c0 MK |
538 | .TP |
539 | .BR MT_ST_FAST_EOM " (Default: false)" | |
979c2c91 | 540 | This option causes the |
e40c76c0 MK |
541 | .B MTEOM |
542 | operation to be sent directly to the | |
fea681da MK |
543 | drive, potentially speeding up the operation but causing the driver to |
544 | lose track of the current file number normally returned by the | |
e40c76c0 MK |
545 | .B MTIOCGET |
546 | request. | |
547 | If | |
548 | .B MT_ST_FAST_EOM | |
c3235368 | 549 | is false, the driver will respond to an |
e40c76c0 MK |
550 | .B MTEOM |
551 | request by forward spacing over files. | |
979c2c91 | 552 | .TP |
e40c76c0 | 553 | .BR MT_ST_AUTO_LOCK " (Default: false)" |
fea681da MK |
554 | When this option is true, the drive door is locked when the device is |
555 | opened and unlocked when it is closed. | |
979c2c91 | 556 | .TP |
e40c76c0 | 557 | .BR MT_ST_DEF_WRITES " (Default: false)" |
fea681da MK |
558 | The tape options (block size, mode, compression, etc.) may change |
559 | when changing from one device linked to a drive to another device | |
560 | linked to the same drive depending on how the devices are | |
c13182ef MK |
561 | defined. |
562 | This option defines when the changes are enforced by the | |
fea681da | 563 | driver using SCSI-commands and when the drives auto-detection |
c13182ef MK |
564 | capabilities are relied upon. |
565 | If this option is false, the driver | |
566 | sends the SCSI-commands immediately when the device is changed. | |
567 | If the | |
fea681da | 568 | option is true, the SCSI-commands are not sent until a write is |
c13182ef | 569 | requested. |
036d0b6d | 570 | In this case, the drive firmware is allowed to detect the |
fea681da MK |
571 | tape structure when reading and the SCSI-commands are used only to |
572 | make sure that a tape is written according to the correct specification. | |
979c2c91 | 573 | .TP |
e40c76c0 | 574 | .BR MT_ST_CAN_BSR " (Default: false)" |
fea681da MK |
575 | When read-ahead is used, the tape must sometimes be spaced backward to the |
576 | correct position when the device is closed and the SCSI command to | |
5fab2e7c | 577 | space backward over records is used for this purpose. |
c13182ef | 578 | Some older |
fea681da | 579 | drives can't process this command reliably and this option can be used |
c13182ef MK |
580 | to instruct the driver not to use the command. |
581 | The end result is that, | |
e2af0daf | 582 | with read-ahead and fixed-block mode, the tape may not be correctly |
c13182ef MK |
583 | positioned within a file when the device is closed. |
584 | With 2.6 kernel, the | |
e2af0daf | 585 | default is true for drives supporting SCSI-3. |
e40c76c0 MK |
586 | .TP |
587 | .BR MT_ST_NO_BLKLIMS " (Default: false)" | |
588 | Some drives don't accept the | |
589 | .B "READ BLOCK LIMITS" | |
590 | SCSI command. | |
591 | If this is used, the driver does not use the command. | |
c13182ef | 592 | The drawback is |
fea681da MK |
593 | that the driver can't check before sending commands if the selected |
594 | block size is acceptable to the drive. | |
e40c76c0 MK |
595 | .TP |
596 | .BR MT_ST_CAN_PARTITIONS " (Default: false)" | |
fea681da | 597 | This option enables support for several partitions within a |
c13182ef MK |
598 | tape. |
599 | The option applies to all devices linked to a drive. | |
e40c76c0 MK |
600 | .TP |
601 | .BR MT_ST_SCSI2LOGICAL " (Default: false)" | |
fea681da MK |
602 | This option instructs the driver to use the logical block addresses |
603 | defined in the SCSI-2 standard when performing the seek and tell | |
e40c76c0 MK |
604 | operations (both with |
605 | .B MTSEEK | |
606 | and | |
607 | .B MTIOCPOS | |
608 | commands and when changing tape | |
c13182ef | 609 | partition). |
2b9b829d | 610 | Otherwise, the device-specific addresses are used. |
fea681da | 611 | It is highly advisable to set this option if the drive supports the |
c13182ef MK |
612 | logical addresses because they count also filemarks. |
613 | There are some | |
33a0ccb2 | 614 | drives that support only the logical block addresses. |
979c2c91 | 615 | .TP |
e40c76c0 | 616 | .BR MT_ST_SYSV " (Default: false)" |
fea681da | 617 | When this option is enabled, the tape devices use the SystemV |
c13182ef | 618 | semantics. |
2b9b829d | 619 | Otherwise, the BSD semantics are used. |
c13182ef | 620 | The most important |
fea681da | 621 | difference between the semantics is what happens when a device used |
80b50848 | 622 | for reading is closed: in System V semantics the tape is spaced forward |
fea681da | 623 | past the next filemark if this has not happened while using the |
c13182ef MK |
624 | device. |
625 | In BSD semantics the tape position is not changed. | |
979c2c91 | 626 | .TP |
e40c76c0 | 627 | .BR MT_NO_WAIT " (Default: false)" |
e2af0daf MK |
628 | Enables immediate mode (i.e., don't wait for the command to finish) for some |
629 | commands (e.g., rewind). | |
e40c76c0 MK |
630 | .PP |
631 | An example: | |
e646a1ba | 632 | .PP |
088a639b | 633 | .in +4n |
e646a1ba | 634 | .EX |
e40c76c0 MK |
635 | struct mtop mt_cmd; |
636 | mt_cmd.mt_op = MTSETDRVBUFFER; | |
637 | mt_cmd.mt_count = MT_ST_BOOLEANS | | |
638 | MT_ST_BUFFER_WRITES | MT_ST_ASYNC_WRITES; | |
639 | ioctl(fd, MTIOCTOP, mt_cmd); | |
b8302363 | 640 | .EE |
e40c76c0 | 641 | .in |
fea681da | 642 | .RE |
fea681da MK |
643 | .IP "" |
644 | The default block size for a device can be set with | |
e40c76c0 MK |
645 | .B MT_ST_DEF_BLKSIZE |
646 | and the default density code can be set with | |
647 | .BR MT_ST_DEFDENSITY . | |
c13182ef | 648 | The values for the parameters are or'ed |
fea681da MK |
649 | with the operation code. |
650 | .IP "" | |
651 | With kernels 2.1.x and later, the timeout values can be set with the | |
e40c76c0 MK |
652 | subcommand |
653 | .B MT_ST_SET_TIMEOUT | |
654 | ORed with the timeout in seconds. | |
fea681da MK |
655 | The long timeout (used for rewinds and other commands |
656 | that may take a long time) can be set with | |
e40c76c0 | 657 | .BR MT_ST_SET_LONG_TIMEOUT . |
c13182ef | 658 | The kernel defaults are very long to |
fea681da | 659 | make sure that a successful command is not timed out with any |
c13182ef | 660 | drive. |
cb3a997e | 661 | Because of this, the driver may seem stuck even if it is only |
c13182ef MK |
662 | waiting for the timeout. |
663 | These commands can be used to set more | |
664 | practical values for a specific drive. | |
665 | The timeouts set for one device | |
fea681da | 666 | apply for all devices linked to the same drive. |
e2af0daf MK |
667 | .IP "" |
668 | Starting from kernels 2.4.19 and 2.5.43, the driver supports a status | |
669 | bit which indicates whether the drive requests cleaning. | |
670 | The method used by the | |
671 | drive to return cleaning information is set using the | |
e40c76c0 MK |
672 | .B MT_ST_SEL_CLN |
673 | subcommand. | |
c13182ef MK |
674 | If the value is zero, the cleaning |
675 | bit is always zero. | |
676 | If the value is one, the TapeAlert data defined | |
677 | in the SCSI-3 standard is used (not yet implemented). | |
9bc87ed0 | 678 | Values 2\(en17 are |
c13182ef MK |
679 | reserved. |
680 | If the lowest eight bits are >= 18, bits from the extended | |
681 | sense data are used. | |
9bc87ed0 MK |
682 | The bits 9\(en16 specify a mask to select the bits |
683 | to look at and the bits 17\(en23 specify the bit pattern to look for. | |
e2af0daf | 684 | If the bit pattern is zero, one or more bits under the mask indicate |
c13182ef | 685 | the cleaning request. |
c7094399 | 686 | If the pattern is nonzero, the pattern must match |
e2af0daf | 687 | the masked sense data byte. |
73d8cece | 688 | .SS MTIOCGET \(em get status |
fea681da MK |
689 | .PP |
690 | This request takes an argument of type | |
5049da5b | 691 | .IR "(struct mtget\ *)" . |
fea681da | 692 | .PP |
088a639b | 693 | .in +4n |
b8302363 | 694 | .EX |
e40c76c0 | 695 | /* structure for MTIOCGET \- mag tape get status command */ |
fea681da | 696 | struct mtget { |
cf0a9ace MK |
697 | long mt_type; |
698 | long mt_resid; | |
e2af0daf | 699 | /* the following registers are device dependent */ |
cf0a9ace MK |
700 | long mt_dsreg; |
701 | long mt_gstat; | |
702 | long mt_erreg; | |
e2af0daf | 703 | /* The next two fields are not always used */ |
cf0a9ace MK |
704 | daddr_t mt_fileno; |
705 | daddr_t mt_blkno; | |
fea681da | 706 | }; |
b8302363 | 707 | .EE |
e40c76c0 | 708 | .in |
f19a0f03 | 709 | .IP \fImt_type\fP 11 |
fea681da | 710 | The header file defines many values for |
f19a0f03 | 711 | .IR mt_type , |
fea681da | 712 | but the current driver reports only the generic types |
e40c76c0 MK |
713 | .B MT_ISSCSI1 |
714 | (Generic SCSI-1 tape) | |
715 | and | |
716 | .B MT_ISSCSI2 | |
717 | (Generic SCSI-2 tape). | |
f19a0f03 | 718 | .IP \fImt_resid\fP |
fea681da | 719 | contains the current tape partition number. |
f19a0f03 | 720 | .IP \fImt_dsreg\fP |
fea681da MK |
721 | reports the drive's current settings for block size (in the low 24 |
722 | bits) and density (in the high 8 bits). | |
e40c76c0 | 723 | These fields are defined by |
979c2c91 | 724 | .BR MT_ST_BLKSIZE_SHIFT , |
e40c76c0 MK |
725 | .BR MT_ST_BLKSIZE_MASK , |
726 | .BR MT_ST_DENSITY_SHIFT , | |
727 | and | |
728 | .BR MT_ST_DENSITY_MASK . | |
f19a0f03 | 729 | .IP \fImt_gstat\fP |
fea681da MK |
730 | reports generic (device independent) status information. |
731 | The header file defines macros for testing these status bits: | |
732 | .RS | |
733 | .HP 4 | |
e40c76c0 | 734 | \fBGMT_EOF\fP(\fIx\fP): |
fea681da | 735 | The tape is positioned just after a filemark |
979c2c91 | 736 | (always false after an |
e40c76c0 MK |
737 | .B MTSEEK |
738 | operation). | |
fea681da | 739 | .HP |
e40c76c0 | 740 | \fBGMT_BOT\fP(\fIx\fP): |
fea681da | 741 | The tape is positioned at the beginning of the first file (always false |
e40c76c0 MK |
742 | after an |
743 | .B MTSEEK | |
744 | operation). | |
fea681da | 745 | .HP |
e40c76c0 | 746 | \fBGMT_EOT\fP(\fIx\fP): |
fea681da MK |
747 | A tape operation has reached the physical End Of Tape. |
748 | .HP | |
e40c76c0 | 749 | \fBGMT_SM\fP(\fIx\fP): |
fea681da | 750 | The tape is currently positioned at a setmark |
e40c76c0 MK |
751 | (always false after an |
752 | .B MTSEEK | |
753 | operation). | |
fea681da | 754 | .HP |
e40c76c0 | 755 | \fBGMT_EOD\fP(\fIx\fP): |
fea681da MK |
756 | The tape is positioned at the end of recorded data. |
757 | .HP | |
e40c76c0 | 758 | \fBGMT_WR_PROT\fP(\fIx\fP): |
fea681da MK |
759 | The drive is write-protected. |
760 | For some drives this can also mean that the drive does not support | |
761 | writing on the current medium type. | |
762 | .HP | |
e40c76c0 | 763 | \fBGMT_ONLINE\fP(\fIx\fP): |
fea681da | 764 | The last |
5e21af3a | 765 | .BR open (2) |
fea681da MK |
766 | found the drive with a tape in place and ready for operation. |
767 | .HP | |
e40c76c0 | 768 | \fBGMT_D_6250\fP(\fIx\fP), \fBGMT_D_1600\fP(\fIx\fP), \fBGMT_D_800\fP(\fIx\fP): |
fea681da MK |
769 | This \(lqgeneric\(rq status information reports the current |
770 | density setting for 9-track \(12" tape drives only. | |
771 | .HP | |
e40c76c0 | 772 | \fBGMT_DR_OPEN\fP(\fIx\fP): |
fea681da MK |
773 | The drive does not have a tape in place. |
774 | .HP | |
e40c76c0 | 775 | \fBGMT_IM_REP_EN\fP(\fIx\fP): |
c13182ef MK |
776 | Immediate report mode. |
777 | This bit is set if there are no guarantees that | |
fea681da | 778 | the data has been physically written to the tape when the write call |
c13182ef MK |
779 | returns. |
780 | It is set zero only when the driver does not buffer data and | |
fea681da | 781 | the drive is set not to buffer data. |
e2af0daf | 782 | .HP |
e40c76c0 | 783 | \fBGMT_CLN\fP(\fIx\fP): |
c13182ef | 784 | The drive has requested cleaning. |
74aace8a | 785 | Implemented in kernels since 2.4.19 and 2.5.43. |
fea681da | 786 | .RE |
f19a0f03 | 787 | .IP \fImt_erreg\fP |
fea681da | 788 | The only field defined in |
f19a0f03 | 789 | .I mt_erreg |
fea681da | 790 | is the recovered error count in the low 16 bits (as defined by |
e40c76c0 MK |
791 | .BR MT_ST_SOFTERR_SHIFT |
792 | and | |
793 | .BR MT_ST_SOFTERR_MASK . | |
fea681da MK |
794 | Due to inconsistencies in the way drives report recovered errors, this |
795 | count is often not maintained (most drives do not by default report | |
796 | soft errors but this can be changed with a SCSI MODE SELECT command). | |
f19a0f03 | 797 | .IP \fImt_fileno\fP |
fea681da MK |
798 | reports the current file number (zero-based). |
799 | This value is set to \-1 when the file number is unknown (e.g., after | |
e40c76c0 MK |
800 | .BR MTBSS |
801 | or | |
802 | .BR MTSEEK ). | |
f19a0f03 | 803 | .IP \fImt_blkno\fP |
fea681da MK |
804 | reports the block number (zero-based) within the current file. |
805 | This value is set to \-1 when the block number is unknown (e.g., after | |
e40c76c0 MK |
806 | .BR MTBSF , |
807 | .BR MTBSS , | |
808 | or | |
809 | .BR MTSEEK ). | |
73d8cece | 810 | .SS MTIOCPOS \(em get tape position |
fea681da MK |
811 | .PP |
812 | This request takes an argument of type | |
5049da5b | 813 | .I "(struct mtpos\ *)" |
fea681da MK |
814 | and reports the drive's notion of the current tape block number, |
815 | which is not the same as | |
f19a0f03 | 816 | .I mt_blkno |
e40c76c0 MK |
817 | returned by |
818 | .BR MTIOCGET . | |
979c2c91 | 819 | This drive must be a SCSI-2 drive that supports the |
e40c76c0 | 820 | .B "READ POSITION" |
fea681da MK |
821 | command (device-specific address) |
822 | or a Tandberg-compatible SCSI-1 drive (Tandberg, Archive | |
823 | Viper, Wangtek, ... ). | |
824 | .PP | |
088a639b | 825 | .in +4n |
b8302363 | 826 | .EX |
e40c76c0 | 827 | /* structure for MTIOCPOS \- mag tape get position command */ |
cf0a9ace MK |
828 | struct mtpos { |
829 | long mt_blkno; /* current block number */ | |
fea681da | 830 | }; |
b8302363 | 831 | .EE |
e40c76c0 | 832 | .in |
47297adb | 833 | .SH RETURN VALUE |
e40c76c0 MK |
834 | .TP 14 |
835 | .TP | |
836 | .B EACCES | |
fea681da MK |
837 | An attempt was made to write or erase a write-protected tape. |
838 | (This error is not detected during | |
5e21af3a | 839 | .BR open (2).) |
e40c76c0 MK |
840 | .TP |
841 | .B EBUSY | |
fea681da MK |
842 | The device is already in use or the driver was unable to allocate a |
843 | buffer. | |
e40c76c0 MK |
844 | .TP |
845 | .B EFAULT | |
846 | The command parameters point to memory not belonging to the calling | |
847 | process. | |
848 | .TP | |
849 | .B EINVAL | |
fea681da | 850 | An |
5e21af3a | 851 | .BR ioctl (2) |
e935e108 | 852 | had an invalid argument, or a requested block size was invalid. |
e40c76c0 MK |
853 | .TP |
854 | .B EIO | |
855 | The requested operation could not be completed. | |
856 | .TP | |
857 | .B ENOMEM | |
858 | The byte count in | |
859 | .BR read (2) | |
860 | is smaller than the next physical block on the tape. | |
d6bec36e MK |
861 | (Before 2.2.18 and 2.4.0 the extra bytes have been |
862 | .\" Precisely: Linux 2.6.0-test6 | |
e40c76c0 MK |
863 | silently ignored.) |
864 | .TP | |
865 | .B ENOSPC | |
866 | A write operation could not be completed because the tape reached | |
867 | end-of-medium. | |
868 | .TP | |
869 | .B ENOSYS | |
fea681da | 870 | Unknown |
5e21af3a | 871 | .BR ioctl (2). |
e40c76c0 MK |
872 | .TP |
873 | .B ENXIO | |
874 | During opening, the tape device does not exist. | |
875 | .TP | |
876 | .B EOVERFLOW | |
877 | An attempt was made to read or write a variable-length block that is | |
878 | larger than the driver's internal buffer. | |
879 | .TP | |
880 | .B EROFS | |
881 | Open is attempted with | |
882 | .B O_WRONLY | |
883 | or | |
884 | .B O_RDWR | |
885 | when the tape in the drive is write-protected. | |
fea681da | 886 | .SH FILES |
cee1a3fc | 887 | .TP |
cba04495 MK |
888 | .I /dev/st* |
889 | the auto-rewind SCSI tape devices | |
cee1a3fc | 890 | .TP |
cba04495 | 891 | .I /dev/nst* |
24b74457 | 892 | the nonrewind SCSI tape devices |
d2dc6294 MK |
893 | .\" .SH AUTHOR |
894 | .\" The driver has been written by Kai M\(:akisara (Kai.Makisara@metla.fi) | |
895 | .\" starting from a driver written by Dwayne Forsyth. | |
896 | .\" Several other | |
897 | .\" people have also contributed to the driver. | |
fea681da | 898 | .SH NOTES |
e40c76c0 MK |
899 | .IP 1. 4 |
900 | When exchanging data between systems, both systems have to agree on | |
c13182ef MK |
901 | the physical tape block size. |
902 | The parameters of a drive after startup | |
fea681da | 903 | are often not the ones most operating systems use with these |
c13182ef MK |
904 | devices. |
905 | Most systems use drives in variable-block mode if the drive | |
906 | supports that mode. | |
907 | This applies to most modern drives, including | |
908 | DATs, 8mm helical scan drives, DLTs, etc. | |
909 | It may be advisable to use | |
e40c76c0 MK |
910 | these drives in variable-block mode also in Linux (i.e., use |
911 | .B MTSETBLK | |
912 | or | |
913 | .B MTSETDEFBLK | |
914 | at system startup to set the mode), at least when | |
c13182ef MK |
915 | exchanging data with a foreign system. |
916 | The drawback of | |
fea681da MK |
917 | this is that a fairly large tape block size has to be used to get |
918 | acceptable data transfer rates on the SCSI bus. | |
e40c76c0 MK |
919 | .IP 2. |
920 | Many programs (e.g., | |
921 | .BR tar (1)) | |
922 | allow the user to specify the blocking | |
c13182ef MK |
923 | factor on the command line. |
924 | Note that this determines the physical block | |
e2af0daf | 925 | size on tape only in variable-block mode. |
e40c76c0 MK |
926 | .IP 3. |
927 | In order to use SCSI tape drives, the basic SCSI driver, | |
fea681da | 928 | a SCSI-adapter driver and the SCSI tape driver must be either |
c13182ef MK |
929 | configured into the kernel or loaded as modules. |
930 | If the SCSI-tape | |
fea681da MK |
931 | driver is not present, the drive is recognized but the tape support |
932 | described in this page is not available. | |
e40c76c0 MK |
933 | .IP 4. |
934 | The driver writes error messages to the console/log. | |
c13182ef | 935 | The SENSE |
fea681da MK |
936 | codes written into some messages are automatically translated to text |
937 | if verbose SCSI messages are enabled in kernel configuration. | |
e40c76c0 MK |
938 | .IP 5. |
939 | The driver's internal buffering allows good throughput in fixed-block | |
c13182ef | 940 | mode also with small |
5e21af3a | 941 | .BR read (2) |
c13182ef | 942 | and |
5e21af3a | 943 | .BR write (2) |
c13182ef MK |
944 | byte counts. |
945 | With direct transfers | |
e2af0daf MK |
946 | this is not possible and may cause a surprise when moving to the 2.6 |
947 | kernel. | |
948 | The solution is to tell the software to use larger transfers (often | |
949 | telling it to use larger blocks). | |
950 | If this is not possible, direct transfers can be disabled. | |
47297adb | 951 | .SH SEE ALSO |
e37e3282 | 952 | .BR mt (1) |
fea681da | 953 | .PP |
cba04495 MK |
954 | The file |
955 | .I drivers/scsi/README.st | |
956 | or | |
957 | .I Documentation/scsi/st.txt | |
173fe7e7 | 958 | (kernel >= 2.6) in the Linux kernel source tree contains |
e37e3282 | 959 | the most recent information about the driver and its configuration |
173fe7e7 | 960 | possibilities |