Initial commit
This commit is contained in:
Ole André Vadla Ravnås
commit
169c65d57e
51358 changed files with 23120455 additions and 0 deletions
218
Documentation/scsi/osst.txt
Normal file
218
Documentation/scsi/osst.txt
Normal file
|
|
@ -0,0 +1,218 @@
|
|||
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
|
||||
Loading…
Add table
Add a link
Reference in a new issue