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Diffstat (limited to 'Documentation/scsi')
| -rw-r--r-- | Documentation/scsi/osst.txt | 218 |
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diff --git a/Documentation/scsi/osst.txt b/Documentation/scsi/osst.txt deleted file mode 100644 index 00c8ebb2fd18..000000000000 --- a/Documentation/scsi/osst.txt +++ /dev/null @@ -1,218 +0,0 @@ -README file for the osst driver -=============================== -(w) Kurt Garloff <garloff@suse.de> 12/2000 - -This file describes the osst driver as of version 0.8.x/0.9.x, the released -version of the osst driver. -It is intended to help advanced users to understand the role of osst and to -get them started using (and maybe debugging) it. -It won't address issues like "How do I compile a kernel?" or "How do I load -a module?", as these are too basic. -Once the OnStream got merged into the official kernel, the distro makers -will provide the OnStream support for those who are not familiar with -hacking their kernels. - - -Purpose -------- -The osst driver was developed, because the standard SCSI tape driver in -Linux, st, does not support the OnStream SC-x0 SCSI tape. The st is not to -blame for that, as the OnStream tape drives do not support the standard SCSI -command set for Serial Access Storage Devices (SASDs), which basically -corresponds to the QIC-157 spec. -Nevertheless, the OnStream tapes are nice pieces of hardware and therefore -the osst driver has been written to make these tape devs supported by Linux. -The driver is free software. It's released under the GNU GPL and planned to -be integrated into the mainstream kernel. - - -Implementation --------------- -The osst is a new high-level SCSI driver, just like st, sr, sd and sg. It -can be compiled into the kernel or loaded as a module. -As it represents a new device, it got assigned a new device node: /dev/osstX -are character devices with major no 206 and minor numbers like the /dev/stX -devices. If those are not present, you may create them by calling -Makedevs.sh as root (see below). -The driver started being a copy of st and as such, the osst devices' -behavior looks very much the same as st to the userspace applications. - - -History -------- -In the first place, osst shared its identity very much with st. That meant -that it used the same kernel structures and the same device node as st. -So you could only have either of them being present in the kernel. This has -been fixed by registering an own device, now. -st and osst can coexist, each only accessing the devices it can support by -themselves. - - -Installation ------------- -osst got integrated into the linux kernel. Select it during kernel -configuration as module or compile statically into the kernel. -Compile your kernel and install the modules. - -Now, your osst driver is inside the kernel or available as a module, -depending on your choice during kernel config. You may still need to create -the device nodes by calling the Makedevs.sh script (see below) manually. - -To load your module, you may use the command -modprobe osst -as root. dmesg should show you, whether your OnStream tapes have been -recognized. - -If you want to have the module autoloaded on access to /dev/osst, you may -add something like -alias char-major-206 osst -to a file under /etc/modprobe.d/ directory. - -You may find it convenient to create a symbolic link -ln -s nosst0 /dev/tape -to make programs assuming a default name of /dev/tape more convenient to -use. - -The device nodes for osst have to be created. Use the Makedevs.sh script -attached to this file. - - -Using it --------- -You may use the OnStream tape driver with your standard backup software, -which may be tar, cpio, amanda, arkeia, BRU, Lone Tar, ... -by specifying /dev/(n)osst0 as the tape device to use or using the above -symlink trick. The IOCTLs to control tape operation are also mostly -supported and you may try the mt (or mt_st) program to jump between -filemarks, eject the tape, ... - -There's one limitation: You need to use a block size of 32kB. - -(This limitation is worked on and will be fixed in version 0.8.8 of - this driver.) - -If you just want to get started with standard software, here is an example -for creating and restoring a full backup: -# Backup -tar cvf - / --exclude /proc | buffer -s 32k -m 24M -B -t -o /dev/nosst0 -# Restore -buffer -s 32k -m 8M -B -t -i /dev/osst0 | tar xvf - -C / - -The buffer command has been used to buffer the data before it goes to the -tape (or the file system) in order to smooth out the data stream and prevent -the tape from needing to stop and rewind. The OnStream does have an internal -buffer and a variable speed which help this, but especially on writing, the -buffering still proves useful in most cases. It also pads the data to -guarantees the block size of 32k. (Otherwise you may pass the -b64 option to -tar.) -Expect something like 1.8MB/s for the SC-x0 drives and 0.9MB/s for the DI-30. -The USB drive will give you about 0.7MB/s. -On a fast machine, you may profit from software data compression (z flag for -tar). - - -USB and IDE ------------ -Via the SCSI emulation layers usb-storage and ide-scsi, you can also use the -osst driver to drive the USB-30 and the DI-30 drives. (Unfortunately, there -is no such layer for the parallel port, otherwise the DP-30 would work as -well.) For the USB support, you need the latest 2.4.0-test kernels and the -latest usb-storage driver from -http://www.linux-usb.org/ -http://sourceforge.net/cvs/?group_id=3581 - -Note that the ide-tape driver as of 1.16f uses a slightly outdated on-tape -format and therefore is not completely interoperable with osst tapes. - -The ADR-x0 line is fully SCSI-2 compliant and is supported by st, not osst. -The on-tape format is supposed to be compatible with the one used by osst. - - -Feedback and updates --------------------- -The driver development is coordinated through a mailing list -<osst@linux1.onstream.nl> -a CVS repository and some web pages. -The tester's pages which contain recent news and updated drivers to download -can be found on -http://sourceforge.net/projects/osst/ - -If you find any problems, please have a look at the tester's page in order -to see whether the problem is already known and solved. Otherwise, please -report it to the mailing list. Your feedback is welcome. (This holds also -for reports of successful usage, of course.) -In case of trouble, please do always provide the following info: -* driver and kernel version used (see syslog) -* driver messages (syslog) -* SCSI config and OnStream Firmware (/proc/scsi/scsi) -* description of error. Is it reproducible? -* software and commands used - -You may subscribe to the mailing list, BTW, it's a majordomo list. - - -Status ------- -0.8.0 was the first widespread BETA release. Since then a lot of reports -have been sent, but mostly reported success or only minor trouble. -All the issues have been addressed. -Check the web pages for more info about the current developments. -0.9.x is the tree for the 2.3/2.4 kernel. - - -Acknowledgments ----------------- -The driver has been started by making a copy of Kai Makisara's st driver. -Most of the development has been done by Willem Riede. The presence of the -userspace program osg (onstreamsg) from Terry Hardie has been rather -helpful. The same holds for Gadi Oxman's ide-tape support for the DI-30. -I did add some patches to those drivers as well and coordinated things a -little bit. -Note that most of them did mostly spend their spare time for the creation of -this driver. -The people from OnStream, especially Jack Bombeeck did support this project -and always tried to answer HW or FW related questions. Furthermore, he -pushed the FW developers to do the right things. -SuSE did support this project by allowing me to work on it during my working -time for them and by integrating the driver into their distro. - -More people did help by sending useful comments. Sorry to those who have -been forgotten. Thanks to all the GNU/FSF and Linux developers who made this -platform such an interesting, nice and stable platform. -Thanks go to those who tested the drivers and did send useful reports. Your -help is needed! - - -Makedevs.sh ------------ -#!/bin/sh -# Script to create OnStream SC-x0 device nodes (major 206) -# Usage: Makedevs.sh [nos [path to dev]] -# $Id: README.osst.kernel,v 1.4 2000/12/20 14:13:15 garloff Exp $ -major=206 -nrs=4 -dir=/dev -test -z "$1" || nrs=$1 -test -z "$2" || dir=$2 -declare -i nr -nr=0 -test -d $dir || mkdir -p $dir -while test $nr -lt $nrs; do - mknod $dir/osst$nr c $major $nr - chown 0.disk $dir/osst$nr; chmod 660 $dir/osst$nr; - mknod $dir/nosst$nr c $major $[nr+128] - chown 0.disk $dir/nosst$nr; chmod 660 $dir/nosst$nr; - mknod $dir/osst${nr}l c $major $[nr+32] - chown 0.disk $dir/osst${nr}l; chmod 660 $dir/osst${nr}l; - mknod $dir/nosst${nr}l c $major $[nr+160] - chown 0.disk $dir/nosst${nr}l; chmod 660 $dir/nosst${nr}l; - mknod $dir/osst${nr}m c $major $[nr+64] - chown 0.disk $dir/osst${nr}m; chmod 660 $dir/osst${nr}m; - mknod $dir/nosst${nr}m c $major $[nr+192] - chown 0.disk $dir/nosst${nr}m; chmod 660 $dir/nosst${nr}m; - mknod $dir/osst${nr}a c $major $[nr+96] - chown 0.disk $dir/osst${nr}a; chmod 660 $dir/osst${nr}a; - mknod $dir/nosst${nr}a c $major $[nr+224] - chown 0.disk $dir/nosst${nr}a; chmod 660 $dir/nosst${nr}a; - let nr+=1 -done |