READCD(1) Schily's USER COMMANDS READCD(1)
NNAAMMEE
readcd - read or write data Compact Discs
SSYYNNOOPPSSIISS
rreeaaddccdd ddeevv==_d_e_v_i_c_e [ _o_p_t_i_o_n_s ]
DDEESSCCRRIIPPTTIIOONN
RReeaaddccdd is used to read or write Compact Discs.
The _d_e_v_i_c_e refers to _s_c_s_i_b_u_s/_t_a_r_g_e_t/_l_u_n of the drive. Com-
munication on _S_u_n_O_S is done with the SCSI general driver
ssccgg.. Other operating systems are using a library simula-
tion of this driver. Possible syntax is: ddeevv== _s_c_s_i_-
_b_u_s,_t_a_r_g_e_t,_l_u_n or ddeevv== _t_a_r_g_e_t,_l_u_n. In the latter case,
the drive has to be connected to the default SCSI bus of
the machine. _S_c_s_i_b_u_s, _t_a_r_g_e_t and _l_u_n 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: ddeevv== _d_e_v_i_c_e_-
_n_a_m_e:_s_c_s_i_b_u_s,_t_a_r_g_e_t,_l_u_n or ddeevv== _d_e_v_i_c_e_n_a_m_e:_t_a_r_g_e_t,_l_u_n. If
the name of the device node that has been specified on
such a system refers to exactly one SCSI device, a short-
hand in the form ddeevv== _d_e_v_i_c_e_n_a_m_e:_@ or ddeevv== _d_e_v_i_c_e_-
_n_a_m_e:_@,_l_u_n may be used instead of ddeevv== _d_e_v_i_c_e_n_a_m_e:_s_c_s_i_-
_b_u_s,_t_a_r_g_e_t,_l_u_n.
To access remote SCSI devices, you need to prepend the
SCSI device name by a remote device indicator. The remote
device indicator is either RREEMMOOTTEE::_u_s_e_r_@_h_o_s_t_: or
RREEMMOOTTEE::_h_o_s_t_:
A valid remote SCSI device name may be: RREEMMOOTTEE::_u_s_e_r_@_h_o_s_t_:
to allow remote SCSI bus scanning or
RREEMMOOTTEE::_u_s_e_r_@_h_o_s_t_:_1_,_0_,_0 to access the SCSI device at _h_o_s_t
connected 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
like UUSSCCSSII:: or AATTAAPPII::. To get a list of supported trans-
port layers for your platform, use ddeevv== _H_E_L_P:
To make rreeaaddccdd portable to all UNIX platforms, the syntax
ddeevv== _d_e_v_i_c_e_n_a_m_e:_s_c_s_i_b_u_s,_t_a_r_g_e_t,_l_u_n is 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 a way to specify _s_c_s_i_-
_b_u_s,_t_a_r_g_e_t,_l_u_n.
_S_c_s_i_b_u_s 0 is the default SCSI bus on the machine. Watch
the boot messages for more information or look into
//vvaarr//aaddmm//mmeessssaaggeess for more information about the SCSI con-
figuration of your machine. If you have problems to fig-
ure out what values for _s_c_s_i_b_u_s,_t_a_r_g_e_t,_l_u_n should be used,
try the --ssccaannbbuuss option of ccddrreeccoorrdd.
OOPPTTIIOONNSS
If no options except the _d_e_v_= option have been specified,
rreeaaddccdd goes into interactive mode. Select a primary func-
tion and then follow the instructions.
--vveerrssiioonn
Print version information and exit.
ddeevv==_t_a_r_g_e_t
Sets the SCSI target for the drive, see notes
above. A typical device specification is ddeevv==_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 manu-
als of the target operating system. On a _F_r_e_e_B_S_D
system without _C_A_M support, you need to use the
control device (e.g. _/_d_e_v_/_r_c_d_0_._c_t_l). A correct
device specification in this case may be
ddeevv==_/_d_e_v_/_r_c_d_0_._c_t_l_:_@ .
On Linux, drives connected to a parallel port
adapter are mapped to a virtual SCSI bus. Different
adapters are mapped to different targets on this
virtual SCSI bus.
If no _d_e_v option is present, ccddrreeccoorrdd will try to
get the device from the CCDDRR__DDEEVVIICCEE environment.
If the argument to the ddeevv== option does not contain
the characters ',', '/', '@' or ':', it is inter-
preted as an label name that may be found in the
file /etc/default/cdrecord (see FILES section).
ttiimmeeoouutt==_#
Set the default SCSI command timeout value to _#
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 com-
mand runs correctly with a raised command timeout,
please report the better timeout value and the cor-
responding command to the author of the program.
If no _t_i_m_e_o_u_t option is present, a default timeout
of 40 seconds is used.
ddeebbuugg==_#_, --dd
Set the misc debug value to # (with debug=#) or
increment the misc debug level by one (with -d). If
you specify _-_d_d_, this equals to ddeebbuugg==_2_. This may
help to find problems while opening a driver for
libscg. as well as with sector sizes and sector
types. Using --ddeebbuugg slows down the process and may
be the reason for a buffer underrun.
kkddeebbuugg==#, kkdd==#
Tell the ssccgg-driver to modify the kernel debug
value while SCSI commands are running.
--ssiilleenntt, --ss
Do not print out a status report for failed SCSI
commands.
--vv Increment the level of general verbosity by one.
This is used e.g. to display the progress of the
process.
--VV 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 mes-
sages you should use this flag to get more detailed
output. --VVVV will show data buffer content in addi-
tion. Using --VV or --VVVV slows down the process.
ff==_f_i_l_e Specify the filename where the output should be
written or the inout should be taken from. Using
'-' as filename will cause rreeaaddccdd to use ssttddoouutt
resp. ssttddiinn.
--ww Switch to write mode. If this option is not pre-
sent, rreeaaddccdd reads from the specified device.
--cc22ssccaann
Scans the whole CD or the range specified by the
sseeccttoorrss==_r_a_n_g_e for C2 errors. C2 errors are errors
that are uncorrectable after the second stage 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 needed to hide
the errors. If a data CD has C2 errors, these
errors are in most cases corrected by the ECC/EDC
code that makes 2352 bytes out of 2048 data bytes.
The ECC/EDC code should be able to correct about
100 C2 error bytes per sector.
If you find C2 errors you may want to reduce the
speed using the ssppeeeedd== option as C2 errors may be a
result of dynamic unbalance on the medium.
sseeccttoorrss==_r_a_n_g_e
Specify a sector range that should be read. The
range is specified by the starting sector number, a
minus sign and the ending sector number. The end
sector is not included in the list, so sseeccttoorrss==0-0
will not read anything and may be used to check for
a CD in the drive.
ssppeeeedd==#
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 _s_p_e_e_d
option is present, rreeaaddccdd will 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.
--nnoottrruunncc
Do not truncate the outputfile when opening it.
--ffuullllttoocc
Retrieve a full TOC from the current disk and print
it in hex.
--cclloonnee 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 the ff== option
but the suffix ..ttoocc added.
--nnooeerrrroorr
Do not abort if the high level error checking in
rreeaaddccdd found an uncorrectable error in the data
stream.
--nnooccoorrrr
Switch the drive into a mode where it ignores read
errors in data sectors that are a result of uncor-
rectable ECC/EDC errors before reading. If rreeaaddccdd
completes, the error recovery mode of the drive is
switched back to the remembered old mode.
rreettrriieess==_#
Set the retry count for high level retries in
rreeaaddccdd to _#. The default is to do 128 retries
which may be too much if you like to read a CD with
many unreadable sectors.
--oovveerrhheeaadd
Meter the SCSI command overhead time. This is done
by executing several commands 1000 times and print-
ing the total time used. If you divide the dis-
played times by 1000, you get the average overhead
time for a single command.
EEXXAAMMPPLLEESS
For all examples below, it will be assumed that the drive
is connected to the primary SCSI bus of the machine. The
SCSI target id is set to 2.
To read the complete media from a CD-ROM writing the data
to the file _c_d_i_m_a_g_e_._r_a_w:
readcd dev=2,0 f=cdimage.raw
To read sectors from range 150 ... 10000 from a CD-ROM
writing the data to the file _c_d_i_m_a_g_e_._r_a_w:
readcd dev=2,0 sectors=150-10000 f=cdimage.raw
To write the data from the file _c_d_i_m_a_g_e_._r_a_w (e.g. a
filesystem image from mmkkiissooffss) to a DVD-RAM, call:
readcd dev=2,0 -w f=cdimage.raw
EENNVVIIRROONNMMEENNTT
RRSSHH If the RRSSHH environment is present, the remote con-
nection will not be created via rrccmmdd(3) but by
calling the program pointed to by RRSSHH. Use e.g.
RRSSHH==/usr/bin/ssh to create a secure shell connec-
tion.
Note that this forces ccddrreeccoorrdd to create a pipe to
the rrsshh((11)) program and disallows ccddrreeccoorrdd to
directly access the network socket to the remote
server. This makes it impossible to set up perfor-
mance parameters and slows down the connection com-
pared to a rroooott initiated rrccmmdd((33)) connection.
RRSSCCSSII If the RRSSCCSSII environment is present, the remote
SCSI server will not be the program
//oopptt//sscchhiillyy//ssbbiinn//rrssccssii but the program pointed to
by RRSSCCSSII. 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.
FFIILLEESS
SSEEEE AALLSSOO
ccddrreeccoorrdd(1), mmkkiissooffss(1), ssccgg(7), ffbbkk(7), rrccmmdd(3), sssshh(1).
NNOOTTEESS
If you don't want to allow users to become root on your
system, rreeaaddccdd may safely be installed suid root. This
allows all users or a group of users with no root privi-
leges to use rreeaaddccdd.. RReeaaddccdd in this case will only allow
access to CD-ROM type drives- To give all user access to
use rreeaaddccdd,, enter:
chown root /usr/local/bin/readcd
chmod 4711 /usr/local/bin/readcd
To give a restricted group of users access to rreeaaddccdd
enter:
chown root /usr/local/bin/readcd
chgrp cdburners /usr/local/bin/readcd
chmod 4710 /usr/local/bin/readcd
and add a group _c_d_b_u_r_n_e_r_s on your system.
Never give write permissions for non root users to the
_/_d_e_v_/_s_c_g_? devices unless you would allow anybody to
read/write/format all your disks.
You should not connect old drives that do not support dis-
connect/reconnect to either the SCSI bus that is connected
to the CD-Recorder or the source disk.
When using rreeaaddccdd with the broken LLiinnuuxx SSCCSSII ggeenneerriicc
ddrriivveerr.. You should note that rreeaaddccdd uses a hack, that
tries to emulate the functionality of the scg driver.
Unfortunately, the sg driver on LLiinnuuxx has several severe
bugs:
+o It cannot see if a SCSI command could not be sent
at all.
+o It cannot get the SCSI status byte. RReeaaddccdd for
that reason cannot report failing SCSI commands in
some situations.
+o It cannot get real DMA count of transfer. RReeaaddccdd
cannot tell you if there is an DMA residual count.
+o It cannot get number of bytes valid in auto sense
data. RReeaaddccdd cannot tell you if device transfers
no sense data at all.
+o It fetches to few data in auto request sense
(CCS/SCSI-2/SCSI-3 needs >= 18).
DDIIAAGGNNOOSSTTIICCSS
A typical error message for a SCSI command looks like:
readcd: 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
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 ker-
nel. It usually is: II//OO eerrrroorr unless other problems hap-
pen. 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. ffaattaall eerrrroorr means that it was not pos-
sible to transport the command (i.e. no device present at
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, followed by the segment number that is only
valid if the command was a _c_o_p_y command. If the error mes-
sage is not directly related to the current command, the
text _d_e_f_e_r_r_e_d _e_r_r_o_r is 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 tables in
_s_c_s_i_e_r_r_s_._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 command and 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 time that the command really needed to complete.
BBUUGGSS
CCRREEDDIITTSS
MMAAIILLIINNGG LLIISSTTSS
If you want to actively take part on the development of
cdrecord, you may join the cdwriting mailing list by send-
ing mail to:
other-cdwrite-request@lists.debian.org
and include the word _s_u_b_s_c_r_i_b_e in the body. The mail
address of the list is:
cdwrite@lists.debian.org
AAUUTTHHOORR
Joerg Schilling
Seestr. 110
D-13353 Berlin
Germany
Additional information can be found on:
http://www.fokus.fhg.de/usr/schilling/cdrecord.html
If you have support questions, send them to:
ccddrreeccoorrdd--ssuuppppoorrtt@@bbeerrlliiooss..ddee
or ootthheerr--ccddwwrriittee@@lliissttss..ddeebbiiaann..oorrgg
Of you have definitely found a bug, send a mail to:
ccddrreeccoorrdd--ddeevveellooppeerrss@@bbeerrlliiooss..ddee
or sscchhiilllliinngg@@ffookkuuss..ffhhgg..ddee
To subscribe, use:
hhttttpp::////lliissttss..bbeerrlliiooss..ddee//mmaaiillmmaann//lliissttiinnffoo//ccddrreeccoorrdd--ddeevveelloopp--
eerrss
or hhttttpp::////lliissttss..bbeerrlliiooss..ddee//mmaaiillmmaann//lliissttiinnffoo//ccddrreeccoorrdd--ssuupp--
ppoorrtt
Joerg Schilling Version 2.0 READCD(1)