1READOM(1) Schily´s USER COMMANDS READOM(1)
2
6 readom - read or write data Compact Discs
7
9 readom dev=device [ options ]
10
13 Readom is used to read or write Compact Discs.
14 The device refers to a device location similar to the one used in the
16 wodim command. Refer to its manpage for details.
17 Also note that this version of readom uses a modified libusal library
19 which has a different behaviour compared to the one distributed by its
20 original author.
21
24 If no options except the dev= option have been specified, readom goes
25 into interactive mode. Select a primary function and then follow the
26 instructions.
27 -version
29 Print version information and exit.
30 dev=target
32 Sets the SCSI target for the drive, see notes above. A typical
33 device specification is dev=6,0 . If a filename must be pro‐
34 vided together with the numerical target specification, the
35 filename is implementation specific. The correct filename in
36 this case can be found in the system specific manuals of the
37 target operating system. On a FreeBSD system without CAM sup‐
38 port, you need to use the control device (e.g. /dev/rcd0.ctl).
39 A correct device specification in this case may be
40 dev=/dev/rcd0.ctl:@ .
41 On Linux, drives connected to a parallel port adapter are mapped
43 to a virtual SCSI bus. Different adapters are mapped to differ‐
44 ent targets on this virtual SCSI bus.
45 If no dev option is present, readom will try to get the device
47 from the CDR_DEVICE environment.
48 If the argument to the dev= option does not contain the charac‐
50 ters ',', '/', '@' or ':', it is interpreted as an label name
51 that may be found in the file /etc/wodim.conf (see FILES sec‐
52 tion).
53 timeout=#
55 Set the default SCSI command timeout value to # seconds. The
56 default SCSI command timeout is the minimum timeout used for
57 sending SCSI commands. If a SCSI command fails due to a time‐
58 out, you may try to raise the default SCSI command timeout above
59 the timeout value of the failed command. If the command runs
60 correctly with a raised command timeout, please report the bet‐
61 ter timeout value and the corresponding command to the author of
62 the program. If no timeout option is present, a default timeout
63 of 40 seconds is used.
64 debug=#, -d
66 Set the misc debug value to # (with debug=#) or increment the
67 misc debug level by one (with -d). If you specify -dd, this
68 equals to debug=2. This may help to find problems while opening
69 a driver for libusal. as well as with sector sizes and sector
70 types. Using -debug slows down the process and may be the rea‐
71 son for a buffer underrun.
72 kdebug=#, kd=#
74 Tell the usal-driver to modify the kernel debug value while SCSI
75 commands are running.
76 -silent, -s
78 Do not print out a status report for failed SCSI commands.
79 -v Increment the level of general verbosity by one. This is used
81 e.g. to display the progress of the process.
82 -V Increment the verbose level with respect of SCSI command trans‐
84 port by one. This helps to debug problems during the process,
85 that occur in the CD-Recorder. If you get incomprehensible
86 error messages you should use this flag to get more detailed
87 output. -VV will show data buffer content in addition. Using
88 -V or -VV slows down the process.
89 f=file Specify the filename where the output should be written or the
91 input should be taken from. Using '-' as filename will cause
92 readom to use stdout resp. stdin.
93 -w Switch to write mode. If this option is not present, readom
95 reads from the specified device.
96 -c2scan
98 Scans the whole CD or the range specified by the sectors=range
99 for C2 errors. C2 errors are errors that are uncorrectable after
100 the second stage of the 24/28 + 28/32 Reed Solomon correction
101 system at audio level (2352 bytes sector size). If an audio CD
102 has C2 errors, interpolation is needed to hide the errors. If a
103 data CD has C2 errors, these errors are in most cases corrected
104 by the ECC/EDC code that makes 2352 bytes out of 2048 data
105 bytes. The ECC/EDC code should be able to correct about 100 C2
106 error bytes per sector.
107 If you find C2 errors you may want to reduce the speed using the
109 speed= option as C2 errors may be a result of dynamic unbalance
110 on the medium.
111 -scanbus
113 Scan all SCSI devices on all SCSI busses and print the inquiry
114 strings. This option may be used to find SCSI address of the
115 devices on a system. The numbers printed out as labels are com‐
116 puted by: bus * 100 + target
117 sectors=range
119 Specify a sector range that should be read. The range is speci‐
120 fied by the starting sector number, a minus sign and the ending
121 sector number. The end sector is not included in the list, so
122 sectors=0-0 will not read anything and may be used to check for
123 a CD in the drive.
124 speed=#
126 Set the speed factor of the read or write process to #. # is an
127 integer, representing a multiple of the audio speed. This is
128 about 150 KB/s for CD-ROM and about 172 KB/s for CD-Audio. If
129 no speed option is present, readom will use maximum speed. Only
130 MMC compliant drives will benefit from this option. The speed
131 of non MMC drives is not changed.
132 Using a lower speed may increase the readability of a CD or DVD.
134 ts=# Set the maximum transfer size for a single SCSI command to #.
136 The syntax for the ts= option is the same as for wodim fs=# or
137 sdd bs=#.
138 If no ts= option has been specified, readom defaults to a trans‐
140 fer size of 256 kB. If libusal gets lower values from the oper‐
141 ating system, the value is reduced to the maximum value that is
142 possible with the current operating system. Sometimes, it may
143 help to further reduce the transfer size or to enhance it, but
144 note that it may take a long time to find a better value by
145 experimenting with the ts= option.
146 -notrunc
148 Do not truncate the output file when opening it.
149 -fulltoc
151 Retrieve a full TOC from the current disk and print it in hex.
152 -clone Do a clone read. Read the CD with all sub-channel data and a
154 full TOC. The full TOC data will be put into a file with simi‐
155 lar name as with the f= option but the suffix .toc added.
156 -noerror
158 Do not abort if the high level error checking in readom found an
159 uncorrectable error in the data stream.
160 -nocorr
162 Switch the drive into a mode where it ignores read errors in
163 data sectors that are a result of uncorrectable ECC/EDC errors
164 before reading. If readom completes, the error recovery mode of
165 the drive is switched back to the remembered old mode.
166 retries=#
168 Set the retry count for high level retries in readom to #. The
169 default is to do 128 retries which may be too much if you like
170 to read a CD with many unreadable sectors.
171 -overhead
173 Meter the SCSI command overhead time. This is done by executing
174 several commands 1000 times and printing the total time used. If
175 you divide the displayed times by 1000, you get the average
176 overhead time for a single command.
177 meshpoints=#
179 Print read-speed at # locations. The purpose of this option is
180 to create a list of read speed values suitable for e.g. gnu‐
181 plot. The speed values are calculated assuming that 1000 bytes
182 are one kilobyte as documented in the SCSI standard. The output
183 data created for this purpose is written to stdout.
184 -factor
186 Output the speed values for meshpoints=# as factor based on sin‐
187 gle speed of the current medium. This only works if readom is
188 able to determine the current medium type.
189
191 For all examples below, it will be assumed that the drive is connected
192 to the primary SCSI bus of the machine. The SCSI target id is set to 2.
193 To read the complete media from a CD-ROM writing the data to the file
195 cdimage.raw:
196 readom dev=2,0 f=cdimage.raw
198 To read sectors from range 150 ... 10000 from a CD-ROM writing the data
200 to the file cdimage.raw:
201 readom dev=2,0 sectors=150-10000 f=cdimage.raw
203 To write the data from the file cdimage.raw (e.g. a filesystem image
205 from genisoimage) to a DVD-RAM, call:
206 readom dev=2,0 -w f=cdimage.raw
208
211 RSH If the RSH environment is present, the remote connection will
212 not be created via rcmd(3) but by calling the program pointed to
213 by RSH. Use e.g. RSH=/usr/bin/ssh to create a secure shell
214 connection.
215 Note that this forces wodim to create a pipe to the rsh(1) pro‐
217 gram and disallows wodim to directly access the network socket
218 to the remote server. This makes it impossible to set up per‐
219 formance parameters and slows down the connection compared to a
220 root initiated rcmd(3) connection.
221 RSCSI If the RSCSI environment is present, the remote SCSI server will
223 not be the program /opt/schily/sbin/rscsi but the program
224 pointed to by RSCSI. Note that the remote SCSI server program
225 name will be ignored if you log in using an account that has
226 been created with a remote SCSI server program as login shell.
227
229 wodim(1), genisoimage(1), rcmd(3), ssh(1).
230
233 Unless you want to risk getting problems, readom should be run as root.
234 If you don't want to allow users to become root on your system, readom
235 may safely be installed suid root. For more information see the addi‐
236 tional notes of your system/program distribution or README.suidroot
237 which is part of the Cdrkit source.
238 Documentation of the wodim program contains more technical details
240 which could also apply to readom.
241
244 A typical error message for a SCSI command looks like:
245 readom: I/O error. test unit ready: scsi sendcmd: no error
247 CDB: 00 20 00 00 00 00
248 status: 0x2 (CHECK CONDITION)
249 Sense Bytes: 70 00 05 00 00 00 00 0A 00 00 00 00 25 00 00 00 00 00
250 Sense Key: 0x5 Illegal Request, Segment 0
251 Sense Code: 0x25 Qual 0x00 (logical unit not supported) Fru 0x0
252 Sense flags: Blk 0 (not valid)
253 cmd finished after 0.002s timeout 40s
254 The first line gives information about the transport of the command.
256 The text after the first colon gives the error text for the system call
257 from the view of the kernel. It usually is: I/O error unless other
258 problems happen. The next words contain a short description for the
259 SCSI command that fails. The rest of the line tells you if there were
260 any problems for the transport of the command over the SCSI bus. fatal
261 error means that it was not possible to transport the command (i.e. no
262 device present at the requested SCSI address).
263 The second line prints the SCSI command descriptor block for the failed
265 command.
266 The third line gives information on the SCSI status code returned by
268 the command, if the transport of the command succeeds. This is error
269 information from the SCSI device.
270 The fourth line is a hex dump of the auto request sense information for
272 the command.
273 The fifth line is the error text for the sense key if available, fol‐
275 lowed by the segment number that is only valid if the command was a
276 copy command. If the error message is not directly related to the cur‐
277 rent command, the text deferred error is appended.
278 The sixth line is the error text for the sense code and the sense qual‐
280 ifier if available. If the type of the device is known, the sense data
281 is decoded from tables in scsierrs.c . The text is followed by the
282 error value for a field replaceable unit.
283 The seventh line prints the block number that is related to the failed
285 command and text for several error flags. The block number may not be
286 valid.
287 The eight line reports the timeout set up for this command and the time
289 that the command really needed to complete.
290
293 The readom program described here is the Cdrkit spinoff from the origi‐
294 nal readcd application (see AUTHOR section for details). It may contain
295 bugs not present in the original implementation.
296 It is definitely less portable than the original implementation.
298 For platform specific bugs, see the corresponding README.platform file
300 in the Cdrkit documentation (eg. README.linux).
301
304 If you want to actively take part on the development of readom, you may
305 join the developer mailing list via this URL:
306 http://alioth.debian.org/mail/?group_id=31006
308 The mail address of the list is: debburn-devel@lists.alioth.debian.org
310
316 Joerg Schilling
317 Seestr. 110
318 D-13353 Berlin
319 Germany
320 This is application is a spinoff from the original implementation of
323 readcd delivered in the cdrtools package [1] created by Joerg
324 Schilling, who deserves the most credits for its success. However, he
325 is not involved into the development of this spinoff and therefore he
326 shall not be made responsible for any problem caused by it. Do not try
327 to get support from the original author!
328 Additional information can be found on:
330 https://alioth.debian.org/projects/debburn/
331 If you have support questions, send them to
333 debburn-devel@lists.alioth.debian.org
335 If you have definitely found a bug, send a mail to this list or to
337 submit@bugs.debian.org
339 writing at least a short description into the Subject and "Package:
341 cdrkit" into the first line of the mail body.
342
344 [1] Cdrtools 2.01.01a08 from May 2006, http://cdrecord.berlios.de
345Joerg Schilling Version 2.0 READOM(1)