summaryrefslogtreecommitdiffstats
path: root/Documentation/scsi/st.txt
Commit message (Collapse)AuthorAgeFilesLines
* st: Fix MTMKPART to work with newer drivesKai Makisara2016-02-231-5/+10
| | | | | | | | | | | | | | | | | Change the MTMKPART operation of the MTIOCTOP ioctl so that it works also with current drives (LTO-5/6, etc.). Send a separate FORMAT MEDIUM command if the partition mode page indicates that this is required. Use LOAD to position the tape at the beginning of tape. The operation is extended so that if the argument is negative, its absolute value specifies the size of partition 0, which is the physically first partition of the tape. Signed-off-by: Kai Mäkisara <kai.makisara@kolumbus.fi> Tested-by: Shane M Seymour <shane.seymour@hpe.com> Tested-by: Laurence Oberman <loberman@redhat.com> Tested-by: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
* st: allow debug output to be enabled or disabled via sysfsSeymour, Shane M2015-11-091-1/+3
| | | | | | | | | | | | | | | | | | | | | | | Change st driver to allow enabling or disabling debug output via sysfs file /sys/bus/scsi/drivers/st/debug_flag. Previously the only way to enable debug output was: 1. loading the driver with the module parameter debug_flag=1 2. an ioctl call (this method was also the only way to dynamically disable debug output). To use the ioctl you need a second tape drive (if you are actively testing the first tape drive) since a second process cannot open the first tape drive if it is in use. The this change is only functional if the value of the macro DEBUG in st.c is a non-zero value (which it is by default). Signed-off-by: Shane Seymour <shane.seymour@hpe.com> Reviewed-by: Laurence Oberman <oberman.l@gmail.com> Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <JBottomley@Odin.com>
* st: implement tape statisticsSeymour, Shane M2015-06-021-0/+59
| | | | | | | | | | | | | | | | | | | | | | This patch implements tape statistics in the st module via sysfs. Current no statistics are available for tape I/O and there is no easy way to reuse the block layer statistics for tape as tape is a character device and does not have perform I/O in sector sized chunks (the size of the data written to tape can change). For tapes we also need extra stats related to things like tape movement (via other I/O). There have been multiple end users requesting statistics including AT&T (and some HP customers who have not given permission to be named). It is impossible for them to investigate any issues related to tape performance in a non-invasive way. [jejb: eliminate PRId64] Signed-off-by: Shane Seymour <shane.seymour@hp.com> Tested-by: Shane Seymour <shane.seymour@hp.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: James Bottomley <JBottomley@Odin.com>
* st: add a debug_flag module parameter requestLaurence Oberman2014-11-121-3/+5
| | | | | | | | | | | This patch adds a debug_flag parameter that can be set on module load, and allows the DEBUG facility without a module recompile. Note that now DEBUG 1 is the default with this patch. Usage: modprobe st debug_flag=1 Signed-off-by: Laurence Oberman <loberman@redhat.com> Acked-by: Kai M??kisara <kai.makisara@kolumbus.fi> Signed-off-by: Christoph Hellwig <hch@lst.de>
* [SCSI] st: raise device limitJeff Mahoney2012-09-141-4/+2
| | | | | | | | | | | | | | | | | | | | | The device limit of 128 tape drives was established in 2003 as a significant increase from the 8 tape drives allowed previously. We're seeing customer sites that between a large number of drives and multipath are discovering more than 128 devices and running into problems. Now that we're not stuck having to store a pointer in array and aren't limited by kmalloc failing on higher order allocs we can lift the limit to fill the entire minor range based on the number of modes. Based on the current code, that's 2^17 devices. Reviewed-by: Lee Duncan <lduncan@suse.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Acked-by: Kai Mäkisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
* [SCSI] st: expand ability to write immediate filemarksLee Duncan2012-03-271-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | The st tape driver recently added the MTWEOFI ioctl, which writes a tape filemark (EOF), like the MTWEOF ioctl, except that MTWEOFI returns immediately. This makes certain applications, like backup software, run much more quickly on buffered tape drives. Since legacy applications do not know about this new MTWEOFI ioctl, this patch adds a new ioctl option that tells the st driver to return immediately when writing an EOF (i.e. a filemark). This new flag is much like the existing flag that tells the st driver to perform writes (and certain other IOs) immediately, but this new flag only applies to writing EOFs. This new feature is controlled via the MTSETDRVBUFFER ioctl, using the newly-defined MT_ST_NOWAIT_EOF flag. Use of this new feature is displayed via the sysfs tape "options" attribute. The st documentation was updated to mention this new flag, as well as the problems that can occur from using it. Signed-off-by: Lee Duncan <lduncan@suse.com> Acked-by: Kai Makisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <JBottomley@Parallels.com>
* [SCSI] st: add MTWEOFI to write filemarks without flushing drive bufferKai Makisara2010-10-081-1/+14
| | | | | | | | | | This patch adds a new MTIOCTOP operation MTWEOFI that writes filemarks with immediate bit set. This means that the drive does not flush its buffer and the next file can be started immediately. This speeds up writing in applications that have to write multiple small files. Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
* [SCSI] st: show options currently set in sysfsKai Makisara2008-04-071-1/+6
| | | | | | | | | | | | | | | Show the current binary tape driver and mode options is sysfs. A file (options) is created in each directory in /sys/class/scsi_tape. The files contain masks showing the options. The mask bit definitions are the same as used when setting the options using the MTSETDRVBUFFER function in the MTIOCTOP ioctl (defined in include/linux/mtio.h). For example: > cat /sys/class/scsi_tape/nst0/options 0x00000d07 [jejb: updated doc with correction from Randy Dunlap] Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* [SCSI] st: add option to use SILI in variable block readsKai Makisara2008-04-071-1/+6
| | | | | | | | | | | Add new option MT_ST_SILI to enable setting the SILI bit in reads in variable block mode. If SILI is set, reading a block shorter than the byte count does not result in CHECK CONDITION. The length of the block is determined using the residual count from the HBA. Avoiding the REQUEST SENSE command for every block speeds up some real applications considerably. Signed-off-by: Kai Makisara <kai.makisara@kolumbus.fi> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
* documentation: convert the Documentation directory to UTF-8John Anthony Kazos Jr2007-05-091-1/+1
| | | | | | | | | | Convert files within the Documentation directory to UTF-8. Adrian Bunk: small additional fixes Signed-off-by: John Anthony Kazos Jr. <jakj@j-a-k-j.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Fix typos in /Documentation : 'T''Matt LaPlante2006-11-301-1/+1
| | | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some +words starting with the letter 'T'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Documentation: remove duplicated wordsPaolo Ornati2006-10-031-1/+1
| | | | | | | | | | | | | | | Remove many duplicated words under Documentation/ and do other small cleanups. Examples: "and and" --> "and" "in in" --> "in" "the the" --> "the" "the the" --> "to the" ... Signed-off-by: Paolo Ornati <ornati@fastwebnet.it> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Fix typos in Documentation/: 'S'Matt LaPlante2006-10-031-1/+1
| | | | | | | | | | This patch fixes typos in various Documentation txts. The patch addresses some words starting with the letter 'S'. Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com> Acked-by: Alan Cox <alan@redhat.com> Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* Linux-2.6.12-rc2v2.6.12-rc2Linus Torvalds2005-04-161-0/+499
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!