Lines Matching +full:scatter +full:- +full:gather
1 .. SPDX-License-Identifier: GPL-2.0
23 flexible method and applicable to single-user workstations. However,
32 drive performs auto-detection of the tape format well (like some
33 QIC-drives). The result is that any tape can be read, writing can be
37 does not perform auto-detection well enough and there is a single
40 or not :-).
57 between formats in multi-tape operations (the explicitly overridden
72 limits). Both the auto-rewind (minor equals device number) and
73 non-rewind devices (minor is 128 + device number) are implemented.
128 dev_upper non-rew mode dev-lower
129 20 - 8 7 6 5 4 0
131 The non-rewind bit is always bit 7 (the uppermost bit in the lowermost
132 byte). The bits defining the mode are below the non-rewind bit. The
143 and non-rewind entries for each mode. The names are stxy and nstxy, where x
151 the defaults set by the user. The value -1 means the default is not set. The
161 directory corresponding to the mode 0 auto-rewind device (e.g., st0).
174 regular expression "^st[0-9]+$"
186 - The number of I/Os currently outstanding to this device.
188 - The amount of time spent waiting (in nanoseconds) for all I/O
193 - The number of I/Os issued to the tape drive other than read or
195 following calculation io_ms-read_ms-write_ms.
197 - The number of bytes read from the tape drive.
199 - The number of read requests issued to the tape drive.
201 - The amount of time (in nanoseconds) spent waiting for read
204 - The number of bytes written to the tape drive.
206 - The number of write requests issued to the tape drive.
208 - The amount of time (in nanoseconds) spent waiting for write
211 - The number of times during a read or write we found
212 the residual amount to be non-zero. This should mean that a program
252 is not possible, a driver buffer allocated at run-time is used. If
257 - one or more pages are at addresses not reachable by the HBA
258 - the number of pages in the transfer exceeds the number of
259 scatter/gather segments permitted by the HBA
260 - one or more pages can't be locked into memory (should not happen in
268 allowed if ST_BUFFER_WRITES is non-zero and direct i/o is not used.
275 -b option) may have had good throughput but this is not true any more with
277 is to use bigger write() byte counts (e.g., tar -b 64).
286 tape after the early-warning mark to flush the driver buffer.
293 Scatter/gather buffers (buffers that consist of chunks non-contiguous
296 supporting scatter/gather), buffer allocation is using the following
300 those not supporting scatter/gather. The size of this buffer will be
307 2. The scatter/gather segments to fill the specified buffer size are
312 are used to extend the buffer at run-time if this is necessary. The
313 number of scatter/gather segments allowed for the SCSI adapter is not
314 exceeded if it is smaller than the maximum number of scatter/gather
325 returns -1 and errno is set to ENOSPC. To enable writing a trailer,
327 bytes is returned. After this, -1 and the number of bytes are
341 max_sg_segs=xxx the maximum number of scatter/gather
344 tape drive if this is non-zero
348 set, the write threshold is set to the new buffer size - 2 kB.
357 with 'st.'. For instance, to set the maximum number of scatter/gather
359 number of scatter/gather segments).
363 the driver as module. If several parameters are set, the keyword-value
376 - aa is the buffer size for fixed block mode in 1024 byte units
377 - bb is the write threshold in 1024 byte units
378 - dd is the maximum number of scatter/gather segments
388 (look for a package mt-st* from the Linux ftp sites; the GNU mt does
426 Re-tension tape.
434 Seek to tape block count. Uses Tandberg-compatible seek (QFA)
435 for SCSI-1 drives and SCSI-2 seek for SCSI-2 drives. The file and
469 partitions (argument non-zero). If the argument is positive,
475 LTO drives from LTO-5 upwards. The drive has to support partitions
519 the MTSEEK and MTIOCPOS for SCSI-2 drives instead of
560 contains the new default. If the bits 8-15 are set to a
561 non-zero number, and this number is not 0xff, the number is
581 cleaning. The bits are device-dependent. The driver is
583 bits of the argument; must be >= 18 (values 1 - 17
585 a mask to select the relevant bits (the bits 9-16), and the
586 bit pattern (bits 17-23). If the bit pattern is zero, one
588 the pattern is non-zero, the pattern must match the masked
599 Tandberg-compatible QFA for SCSI-1 drives and the SCSI-2
600 command for the SCSI-2 drives.
607 block is -1 when it can't be determined (e.g., after MTBSF).
663 the driver is waiting. With the command 'ps -l' you can see the state