MAN page from Old RedHat 7.X cdrtools-1.10a13-1.i386.rpm

READCD

Section: Schily\'s USER COMMANDS (1)
Updated: Version 1.8.1
Index

NAME

readcd - read or write data Compact Discs

SYNOPSIS

readcddev=device[options]

DESCRIPTION

Readcdis used to read or write Compact Discs.

Thedevicerefers toscsibus/target/lunof the drive. Communication on SunOSis done with the SCSI general driverscg.Other operating systems are using a library simulation of this driver.Possible syntax is:dev=scsibus,target,lunordev=target,lun.In the latter case, the drive has to be connected to the default SCSI bus of the machine.Scsibus,target and lunare integer numbers. Some operating systems or SCSI transport implementations may require tospecify a filename in addition.In this case the corect syntax for the device is:dev=devicename:scsibus,target,lunordev=devicename:target,lun.If the name of the device node that has been specified on such a systemreferres to exactly one SCSI device, a shorthand in the formdev=devicename:@ordev=devicename:@,lunmay be used instead ofdev=devicename:scsibus,target,lun.

To make readcdportable to all UNIX platforms, the syntaxdev=devicename:scsibus,target,lunis preferred as is hides OS specific knowledge about device names from the user.A specific OS must not necessarily support a way to specify a real device file name nor away to specify scsibus,target,lun.

Scsibus 0 is the default SCSI bus on the machine. Watch the boot messages for more information or look into /var/adm/messages for more information about the SCSI configuration of your machine.If you have problems to figure out what values for scsibus,target,lunshould be used, try the -scanbusoption of cdrecord.

OPTIONS

If no options except the dev=option have been specified, readcdgoes into intercative mode.Select a primary function and then follow the instructions.

f=file
-version: Print version information and exit.
-v: Increment the level of general verbosity by one.
-V: Increment the verbose level in respect of SCSI command transport by one.This helps to debug problemsduring the writing process, that occur in the drive.If you get incomprehensible error messages you should use this flagto get more detailed output.-VVwill show data buffer content in addition.Using-Vor-VVslows down the process and may be the reason for a buffer underrun.
-w: Switch to write mode. If this option is not present,readcdreads from the specified device.
sectors=range: Specify a sector range that should be read.The range is specified by the starting sector number, a minus sign and theending sector number.
-notrunc: Do not truncate the outputfile when opening it.

EXAMPLES

For all examples below, it will be assumed that the drive isconnected to the primary SCSI bus of the machine. The SCSI target id isset to 2.

To read the complete media from a CD-ROM writing the data to the filecdimage.raw:

readcd dev=2,0 f=cdimage.raw

To read sectors from range 150 ... 10000 from a CD-ROM writing the data to the filecdimage.raw:

readcd dev=2,0 sectors=150-10000 f=cdimage.raw

To write the data from the filecdimage.raw(e.g. a filesystem image from mkisofs)to a DVD-RAM, call:

readcd dev=2,0 -w f=cdimage.raw

FILES

NOTES

If you don't want to allow users to become root on your system,readcdmay safely be installed suid root. This allows all users or a group ofusers with no root privileges to use readcd.Readcdin this case will only allow access to CD-ROM type drives-To give all user access to use readcd, enter:

chown root /usr/local/bin/readcd

chmod 4711 /usr/local/bin/readcd

To give a restricted group of users access to readcdenter:

       chown root /usr/local/bin/readcd

       chgrp cdburners /usr/local/bin/readcd

       chmod 4710 /usr/local/bin/readcd

and add a group cdburnerson your system.

Never give write permissions for non root users to the /dev/scg?devices unless you would allow anybody to read/write/formatall your disks.

You should not connect old drives that do not supportdisconnect/reconnect to either the SCSI bus that is connected to theCD-Recorder or the source disk.

When using readcdwith the broken Linux SCSI generic driver.You should note that readcduses a hack, that tries to emulate the functionality of the scg driver.Unfortunately, the sg driver on Linuxhas several severe bugs:

*: It cannot see if a SCSI command could not be sent at all.
*: It cannot get the SCSI status byte. Readcdfor that reason cannot report failing SCSI commands in somesituations.
*: It cannot get real DMA count of transfer. Readcdcannot tell you if there is an DMA residual count.
*: It cannot get number of bytes valid in auto sense data.Readcdcannot tell you if device transfers no sense data at all.
*: It fetches to few data in auto request sense (CCS/SCSI-2/SCSI-3 needs >= 18).

DIAGNOSTICS

A typical error message for a SCSI command looks like:

readcd: I/O error. test unit ready: scsi sendcmd: no errorCDB:  00 20 00 00 00 00status: 0x2 (CHECK CONDITION)Sense Bytes: 70 00 05 00 00 00 00 0A 00 00 00 00 25 00 00 00 00 00Sense Key: 0x5 Illegal Request, Segment 0Sense Code: 0x25 Qual 0x00 (logical unit not supported) Fru 0x0Sense flags: Blk 0 (not valid)

The first line gives information about the transport of the command.The text after the first colon gives the error text for the system callfrom the view of the kernel. It usually is:I/O errorunless other problems happen. The next words contain a short description forthe SCSI command that fails. The rest of the line tells you if there wereany problems for the transport of the command over the SCSI bus.fatal errormeans that it was not possible to transport the command (i.e. no device presentat the requested SCSI address).

The second line prints the SCSI command descriptor block for the failed command.

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.

The fourth line is a hex dump of the auto request sense information for the command.

The fifth line is the error text for the sense key if available, followedby the segment number that is only valid if the command was acopycommand. If the error message is not directly related to the current command,the textdeferred erroris appended.

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 tablesinscsierrs.c .The text is followed by the error value for a field replaceable unit.

The seventh line prints the block number that is related to the failed commandand text for several error flags. The block number may not be valid.

BUGS

CREDITS

MAILING LISTS

If you want to actively take part on the development of cdrecord,you may join the cdwriting mailing list by sending mail to:

        other-cdwrite-requestAATTlists.debian.org

and include the word subscribein the body.The mail address of the list is:

        cdwriteAATTlists.debian.org

AUTHOR

Joerg SchillingSeestr. 110D-13353 BerlinGermany

Additional information can be found on:
http://www.fokus.gmd.de/usr/schilling/cdrecord.html

Mail bugs and suggestions to:

joergAATTschily.isdn.cs.tu-berlin.deorjsAATTcs.tu-berlin.deorschillingAATTfokus.gmd.de

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