path: root/upstream/archlinux/man1/scgskeleton.1

.\" @(#)scgskeleton.1	1.4 16/01/26 Copyright 1986-2016 J. Schilling
.\" Manual page for scgskeleton
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.TH SCGSKELETON 1L "2016/01/26" "J\*org Schilling" "Schily\'s USER COMMANDS"
.SH NAME
scgskeleton \- Skeleton program for SCSI transport using libscg
.SH SYNOPSIS
.B
scgskeleton
.BI dev= device
[
.I options
]
.SH DESCRIPTION
.B Scgskeleton
is s skeleton program to demonstrate the interfaces and capabilities of the SCSI 
transport library
.BR libscg .
.PP
.SS "Device naming"
For a list of possible device name parameters call
.B "scgskeleton \-scanbus
or
.B "scgskeleton dev=help
and then use the right
.B dev=
parameter based on the device listing.

.SH OPTIONS
.TP
.B \-help
Prints a short summary of the 
.B p
options and exists.
.TP
.B \-version
Print version information and exit.
.TP
.BI dev= target
Set the SCSI target for the CD/DVD/BluRay-Recorder, see notes above.
A typical target device specification is
.BI dev= 1,6,0
\&.
If a filename must be provided together with the numerical target 
specification, the filename is implementation specific.
The correct filename in this case can be found in the system specific
manuals of the target operating system.
On a 
.I FreeBSD
system without 
.I CAM
support, you need to use the control device (e.g.
.IR /dev/rcd0.ctl ).
A correct device specification in this case may be
.BI dev= /dev/rcd0.ctl:@
\&.
.sp
.B \h'-2m'General SCSI addressing
.br
The
.I target device
to the 
.B dev=
option
refers to
.IR scsibus / target / lun
of the CD/DVD/BluRay-Recorder. Communication on 
.I SunOS
is done with the SCSI general driver
.B scg.
Other operating systems are using a library simulation of this driver.
Possible syntax is:
.B dev=
.IR scsibus , target , lun
or
.B dev=
.IR target , lun .
In the latter case, the CD/DVD/BluRay-Recorder has to be connected to the default 
SCSI bus of the machine.
.IR Scsibus ,
.I target 
and 
.I lun
are integer numbers. 
Some operating systems or SCSI transport implementations may require to
specify a filename in addition.
In this case the correct syntax for the device is:
.B dev=
.IR devicename : scsibus , target , lun
or
.B dev=
.IR devicename : target , lun .
If the name of the device node that has been specified on such a system
refers to exactly one SCSI device, a shorthand in the form
.B dev=
.IR devicename : @
or
.B dev=
.IR devicename : @ , lun
may be used instead of
.B dev=
.IR devicename : scsibus , target , lun .
.sp
.B \h'-2m'Remote SCSI addressing
.br
To access remote SCSI devices, you need to prepend the SCSI device name by
a remote device indicator. The remote device indicator is either
.BI REMOTE: user@host:
or
.BI REMOTE: host:
A valid remote SCSI device name may be:
.BI REMOTE: user@host:
to allow remote SCSI bus scanning or
.BI REMOTE: user@host:1,0,0
to access the SCSI device at 
.I host
connected to SCSI bus # 1,target 0, lun 0.
In order to allow remote access to a specific
.IR host ,
the
.BR rscsi (1)
program needs to be present and configured on the
.IR host .
.sp
.B \h'-2m'Alternate SCSI transports
.br
.B ATAPI
drives are just
.B SCSI
drives that inherently use the 
.I "ATA packet interface
as
.B SCSI
command transport layer build into the IDE (ATA) transport.
You may need to specify an alternate transport layer on the command  line
if your OS does not implement a fully integrated kernel driver subsystem that
allows to access any drive using
.B SCSI
commands via a single unique user interface.
.sp
To access SCSI devices via alternate transport layers,
you need to prepend the SCSI device name by a transport layer indicator.
The transport layer indicator may be something like
.B USCSI: 
or
.BR ATAPI: .
To get a list of supported transport layers for your platform, use 
.B dev=
.IR HELP :
.sp
.B \h'-2m'Portability Background
.br
To make 
.B scgskeleton
portable to all \s-2UNIX\s0 platforms, the syntax
.B dev=
.IR devicename : scsibus , target , lun
is preferred as it hides OS specific knowledge about device names from the user.
A specific OS may not necessarily support a way to specify a real device file name nor a
way to specify 
.IR scsibus , target , lun .
.sp
.I Scsibus 
0 is the default SCSI bus on the machine. Watch the boot messages for more 
information or look into 
.B /var/adm/messages 
for more information about the SCSI configuration of your machine.
If you have problems to figure out what values for 
.IR scsibus , target , lun
should be used, try the 
.B \-scanbus
option of 
.B scgskeleton
described below.
.sp
.B \h'-2m'Using logical names for devices
.br
If no 
.I dev
option is present, 
.B scgskeleton
will try to get the device from the 
.B CDR_DEVICE
environment.
.sp
If a file /etc/default/cdrecord exists, and
if the argument to the
.B dev=
option
or the
.B CDR_DEVICE
environment
does not contain the characters ',', '/', '@' or ':',
it is interpreted as a device label name that was defined in the file
/etc/default/cdrecord (see FILES section).
.sp
.B \h'-2m'Autotarget Mode
.br
If no 
.B dev=
option 
and no
.B CDR_DEVICE
environment
is present, or if it
only contains a transport specifyer but no address notation,
.B scgskeleton
tries to scan the SCSI address space for CD-ROM drives.
If exactly one is found, this is used by default.
.TP
.BI timeout= #
Set the default SCSI command timeout value to 
.IR # " seconds.
The default SCSI command timeout is the minimum timeout used for sending
SCSI commands.
If a SCSI command fails due to a timeout, you may try to raise the
default SCSI command timeout above the timeout value of the failed command.
If the command runs correctly with a raised command timeout,
please report the better timeout value and the corresponding command to 
the author of the program.
If no 
.I timeout 
option is present, a default timeout of 40 seconds is used.
.TP
.BI debug= "#, " -d
Set the misc debug value to # (with debug=#) or increment
the misc debug level by one (with -d). If you specify
.I -dd,
this equals to 
.BI debug= 2.
This may help to find problems while opening a driver for libscg.
as well as with sector sizes and sector types.
Using
.B \-debug
slows down the process and may be the reason for a buffer underrun.
.TP
.BR kdebug= "#, " kd= #
Tell the 
.BR scg -driver
to modify the kernel debug value while SCSI commands are running.
.TP
.BR \-silent ", " \-s
Do not print out a status report for failed SCSI commands.
.TP
.B \-v
Increment the level of general verbosity by one.
This is used e.g. to display the progress of the process.
.TP
.B \-V
Increment the verbose level with respect of SCSI command transport by one.
This helps to debug problems
during the process, that occur in the CD-Recorder. 
If you get incomprehensible error messages you should use this flag
to get more detailed output.
.B \-VV
will show data buffer content in addition.
Using
.B \-V
or
.B \-VV
slows down the process.
.B \-scanbus
Scan all SCSI devices on all SCSI busses and print the inquiry
strings. This option may be used to find SCSI address of the 
devices on a system.
The numbers printed out as labels are computed by: 
.B "bus * 100 + target
.TP
.BI scgopts= list
A comma separated list of SCSI options that are handled by libscg.
The implemented options may be uptated indepentendly from applications.
Currently, one option:
.B ignore\-resid
is supported to work around a Linux kernel bug.
.TP
.BR ts= #
Set the maximum transfer size for a single SCSI command to #.
The syntax for the 
.B ts=
option is the same as for cdrecord fs=# or sdd bs=#.
.sp
If no 
.B ts=
option has been specified,
.B scgskeleton
defaults to a transfer size of 256 kB. If libscg gets lower values from the
operating system, the value is reduced to the maximum value that is possible
with the current operating system.
Sometimes, it may help to further reduce the transfer size or to enhance it,
but note that it may take a long time to find a better value by experimenting
with the
.B ts=
option.


.SH EXAMPLES
.SH ENVIRONMENT
.TP
.B RSH
If the 
.B RSH
environment is present, the remote connection will not be created via
.BR rcmd (3)
but by calling the program pointed to by
.BR RSH .
Use e.g. 
.BR RSH= /usr/bin/ssh
to create a secure shell connection.
.sp
Note that this forces 
.B cdrecord
to create a pipe to the 
.B rsh(1)
program and disallows
.B cdrecord
to directly access the network socket to the remote server.
This makes it impossible to set up performance parameters and slows down
the connection compared to a 
.B root
initiated
.B rcmd(3)
connection.
.TP
.B RSCSI
If the 
.B RSCSI
environment is present, the remote SCSI server will not be the program
.B /opt/schily/sbin/rscsi
but the program pointed to by
.BR RSCSI .
Note that the remote SCSI server program name will be ignored if you log in
using an account that has been created with a remote SCSI server program as
login shell.
.SH "SEE ALSO"
.BR cdrecord (1),
.BR scg (7),
.BR rcmd (3),
.BR ssh (1).
.SH NOTES
.SH DIAGNOSTICS
.PP
A typical error message for a SCSI command looks like:
.sp
.RS
.nf
scgskeleton: I/O error. test unit ready: scsi sendcmd: no error
CDB:  00 20 00 00 00 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 05 00 00 00 00 0A 00 00 00 00 25 00 00 00 00 00
Sense Key: 0x5 Illegal Request, Segment 0
Sense Code: 0x25 Qual 0x00 (logical unit not supported) Fru 0x0
Sense flags: Blk 0 (not valid)
cmd finished after 0.002s timeout 40s
.fi
.sp
.RE
The first line gives information about the transport of the command.
The text after the first colon gives the error text for the system call
from the view of the kernel. It usually is:
.B "I/O error
unless other problems happen. The next words contain a short description for
the SCSI command that fails. The rest of the line tells you if there were
any problems for the transport of the command over the SCSI bus.
.B "fatal error
means that it was not possible to transport the command (i.e. no device present
at the requested SCSI address).
.PP
The second line prints the SCSI command descriptor block for the failed command.
.PP
The third line gives information on the SCSI status code returned by the 
command, if the transport of the command succeeds. 
This is error information from the SCSI device.
.PP
The fourth line is a hex dump of the auto request sense information for the 
command.
.PP
The fifth line is the error text for the sense key if available, followed
by the segment number that is only valid if the command was a
.I copy
command. If the error message is not directly related to the current command,
the text
.I deferred error
is appended.
.PP
The sixth line is the error text for the sense code and the sense qualifier if available.
If the type of the device is known, the sense data is decoded from tables
in
.IR scsierrs.c " .
The text is followed by the error value for a field replaceable unit.
.PP
The seventh line prints the block number that is related to the failed command
and text for several error flags. The block number may not be valid.
.PP
The eight line reports the timeout set up for this command and the time
that the command really needed to complete.

.SH BUGS
.SH AUTHOR
.nf
J\*org Schilling
Seestr. 110
D-13353 Berlin
Germany
.fi
.PP
Additional information can be found on:
.br
http://cdrecord.org/private/cdrecord.html
.PP
If you have support questions, send them to:
.PP
.B
cdrtools-support@lists.sourceforge.net
.PP
If you have definitely found a bug, send a mail to:
.PP
.B
cdrtools-developers@lists.sourceforge.net
.br
or
.B
joerg.schilling@fokus.fraunhofer.de
.PP
To subscribe, use:
.PP
.B
https://lists.sourceforge.net/lists/listinfo/cdrtools-developers
.br
or
.B
https://lists.sourceforge.net/lists/listinfo/cdrtools-support