MAN page from Old RedHat 8.X cdrtools-2.0-1.i386.rpm

READCD

Section: Schily\'s USER COMMANDS (1)
Updated: Version 2.0
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 correct 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 systemrefers to exactly one SCSI device, a shorthand in the formdev=devicename:@ordev=devicename:@,lunmay be used instead ofdev=devicename:scsibus,target,lun.

To access remote SCSI devices, you need to prepend the SCSI device name bya remote device indicator. The remote device indicator is eitherREMOTE:userAATThost:or.BIREMOTE:host:
A valid remote SCSI device name may be:REMOTE:userAATThost:to allow remote SCSI bus scanning orREMOTE:userAATThost:1,0,0to access the SCSI device at hostconnected to SCSI bus # 1,target 0 lun 0.

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 likeUSCSI: orATAPI:.To get a list of supported transport layers for your platform, use dev=HELP:

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 interactive mode.Select a primary function and then follow the instructions.

-version

Print version information and exit.

dev=target

Sets the SCSI target for the drive, see notes above.A typical device specification isdev=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 specificmanuals of the target operating system.On a FreeBSDsystem without CAMsupport, you need to use the control device (e.g./dev/rcd0.ctl).A correct device specification in this case may bedev=/dev/rcd0.ctl:@.

On Linux, drives connected to a parallel port adapter are mappedto a virtual SCSI bus. Different adapters are mapped to differenttargets on this virtual SCSI bus.

If no devoption is present, cdrecordwill try to get the device from the CDR_DEVICEenvironment.

If the argument to thedev=option does not contain the characters ',', '/', '@' or ':',it is interpreted as an label name that may be found in the file/etc/default/cdrecord (see FILES section).

timeout=#

Set the default SCSI command timeout value to # seconds.The default SCSI command timeout is the minimum timeout used for sendingSCSI commands.If a SCSI command fails due to a timeout, you may try to raise thedefault 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 timeout option is present, a default timeout of 40 seconds is used.

debug=#, -d

Set the misc debug value to # (with debug=#) or incrementthe misc debug level by one (with -d). If you specify-dd,this equals to debug=2.This may help to find problems while opening a driver for libscg.as well as with sector sizes and sector types.Using-debugslows down the process and may be the reason for a buffer underrun.

kdebug=#, kd=#

Tell the scg-driverto modify the kernel debug value while SCSI commands are running.

-silent, -s

Do not print out a status report for failed SCSI commands.

-v

Increment the level of general verbosity by one.This is used e.g. to display the progress of the process.

-V

Increment the verbose level with respect of SCSI command transport by one.This helps to debug problemsduring the process, that occur in the CD-Recorder. 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.

f=file

Specify the filename where the output should be written or the inout shouldbe taken from. Using '-' as filename will causereadcdto use stdout resp. stdin.

-w

Switch to write mode. If this option is not present,readcdreads from the specified device.

-c2scan

Scans the whole CD or the range specified by the sectors=rangefor C2 errors. C2 errors are errors that are uncorrectable after the secondstage of the 24/28 + 28/32 Reed Solomon correction system at audio level(2352 bytes sector size). If an audio CD has C2 errors, interpolation is neededto hide the errors. If a data CD has C2 errors, these errors are in mostcases corrected by the ECC/EDC code that makes 2352 bytes out of 2048 databytes. The ECC/EDC code should be able to correct about 100 C2 error bytesper sector.

If you find C2 errors you may want to reduce the speed using thespeed=option as C2 errors may be a result of dynamic unbalance on the medium.

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.The end sector is not included in the list, so sectors=0-0will not read anything and may be used to check for a CD in the drive.

speed=#

Set the speed factor of the read or write process to #.# is an integer, representing a multiple of the audio speed.This is about 150 KB/s for CD-ROM and about 172 KB/s for CD-Audio.If no speedoption is present, readcdwill use maximum speed.Only MMC compliant drives will benefit from this option.The speed of non MMC drives is not changed.

Using a lower speed may increase the readability of a CD or DVD.

-notrunc

Do not truncate the outputfile when opening it.

-fulltoc

Retrieve a full TOC from the current disk and print it in hex.

-clone

Do a clone read. Read the CD with all sub-channel data and a full TOC.The full TOC data will be but into a file with similar name as with thef=option but the suffix .tocadded.

-noerror

Do not abort if the high level error checking inreadcdfound an uncorrectable error in the data stream.

-nocorr

Switch the drive into a mode where it ignores read errors in data sectors thatare a result of uncorrectable ECC/EDC errors before reading.Ifreadcdcompletes, the error recovery mode of the drive is switched back to the remembered old mode.

retries=#

Set the retry count for high level retries inreadcdto #.The default is to do 128 retries which may be too much if you like to read a CDwith many unreadable sectors.

-overhead

Meter the SCSI command overhead time.This is done by executing several commands 1000 times and printing thetotal time used. If you divide the displayed times by 1000, you get the average overhead time for a single command.

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

ENVIRONMENT

RSH: If the RSHenvironment is present, the remote connection will not be created viarcmd(3)but by calling the program pointed to byRSH.Use e.g. RSH=/usr/bin/sshto create a secure shell connection.
Note that this forces cdrecordto create a pipe to the rsh(1)program and disallowscdrecordto directly access the network socket to the remote server.This makes it impossible to set up performance parameters and slows downthe connection compared to a rootinitiatedrcmd(3)connection.
RSCSI: If the RSCSIenvironment is present, the remote SCSI server will not be the program/opt/schily/sbin/rscsibut the program pointed to byRSCSI.Note that the remote SCSI server program name will be ignored if you log inusing an account that has been created with a remote SCSI server program aslogin shell.

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)cmd finished after 0.002s timeout 40s

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.

The eight line reports the timeout set up for this command and the timethat the command really needed to complete.

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.fhg.de/usr/schilling/cdrecord.html

If you have support questions, send them to:

cdrecord-supportAATTberlios.de
orother-cdwriteAATTlists.debian.org

Of you have definitely found a bug, send a mail to:

cdrecord-developersAATTberlios.de
orschillingAATTfokus.fhg.de

To subscribe, use:

http://lists.berlios.de/mailman/listinfo/cdrecord-developers
orhttp://lists.berlios.de/mailman/listinfo/cdrecord-support

This document was created byman2html,using the manual pages.