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Things look quiet here. But I've been doing a lot of blogging at
dan.langille.org because I prefer WordPress now.
Not all my posts there are FreeBSD related.
I am in the midst of migrating The FreeBSD Diary over to WordPress
(and you can read about that here).
Once the migration is completed, I'll move the FreeBSD posts into the
new FreeBSD Diary website.
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cdrecord - writing your own CDs
14 December 2000
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While I was at BSDCon
2000, I was able to make a number of purchases. These were wholly/partly funded
by donations and from ad revenue.
One of the items was a Plextor CD-RW internal SCSI
drive. I chose SCSI because of advice I was given regarding SCSI reliability
with respect to CDRW drives. I chose Plextor because of the recommendations of
others. Plextor has also donated several drives to the cdrecord author (see
here
for details), including the drive model I bought. That's a good marketing move by
Plextor. It ensures the author can test and work with their hardware, thereby
ensuring the software works well with that drive.
NOTE: In this article, I specify the speed which should be used to write
to the CD. You should adjust that value to suit your CD drive.
The sharp eyed amongst you may notice that the device used in this article
differs from that used in the cdrecord -
writing multiple sessions article. That's not magic. And it's not a
mistake. When I wrote this article, I had two SCSI cards in the box. I've
since returned one to it's owner and put the CDRW on the same card as the two SCSI drives.
If you are using an IDE CD-RW, you may find Burning CDs on an IDE CD-RW helpful.
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cdrecord resources
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The home page for cdrecord is
http://cdrecord.berlios.de/old/private/cdrecord.html
The FAQ and How-To are at:
http://cdrecord.berlios.de/old/private/man/cdr_readme.html
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Installing
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I have the entire ports tree. So it was
easy. cdrecord is now part of sysutils/cdrtools. When I first
wrote this article, it was in sysutils/cdrecord. To install:
cd /usr/ports/sysutils/cdrtools
make install
You will also need mkisofs (as in Make ISO File System) for creating an ISO
image. It is also in sysutils/cdrtools. In previous times, it was found in sysutils/mkisofs.
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Kernel suggestions
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The notes for FreeBSD users (see above link) suggest that you include the
following options in your kernel:
options P1003_1B #Posix P1003_1B real-time extensions
options _KPOSIX_PRIORITY_SCHEDULING
#
# The above two POSIX options were already in my kernel.
# I added the following for cdrecord.
#
options _KPOSIX_VERSION=199309L
See Building and
Installing a Custom Kernel in the FreeBSD
Handbook for more information on modifying your kernel. |
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Know your CD drive
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In order to use cdrecord, you need to know where your CD drive is installed.
Here's an extract from dmesg on my box:
cd0 at ahc0 bus 0 target 5 lun 0
cd0: <PLEXTOR CD-R PX-W124TS 1.05> Removable CD-ROM SCSI-2 device
cd0: 10.000MB/s transfers (10.000MHz, offset 8)
cd0: cd present [332860 x 2048 byte records]
cdrecord needs the bus, target, and lun values (in the above case, that's
0,5,0).
But beware, cdrecord did not recognize the above. Witness the following
failure (I'll explain what I was doing in the next section):
# cdrecord -dummy -eject blank=all dev=0,5,0
Cdrecord 1.9 (i386-unknown-freebsd4.2)
Copyright (C) 1995-2000 Jörg Schilling
scsidev: '0,5,0'
scsibus: 0 target: 5 lun: 0
cdrecord: No such file or directory. Cannot open SCSI driver.
cdrecord: For possible targets try 'cdrecord -scanbus'. Make sure
you are root.
That was odd. So I took their suggestion and tried the scanbus...
# cdrecord -scanbus
Cdrecord 1.9 (i386-unknown-freebsd4.2)
Copyright (C) 1995-2000 Jörg Schilling
Using libscg version 'schily-0.1'
scsibus0:
0,0,0 0) 'SEAGATE ' 'ST318436LW ' '0010' Disk
0,1,0 1) 'SEAGATE ' 'ST318436LW ' '0010' Disk
0,2,0 2) *
0,3,0 3) *
0,4,0 4) *
0,5,0 5) *
0,6,0 6) *
0,7,0 7) *
scsibus1:
1,0,0 100) *
1,1,0 101) *
1,2,0 102) *
1,3,0 103) *
1,4,0 104) *
1,5,0 105) 'PLEXTOR ' 'CD-R PX-W124TS' '1.05' Removable CD-ROM
1,6,0 106) *
1,7,0 107) *
Ahah! I should be using 1,5,0, not 0,5,0. In the hopes that the following
may be helpful to someone, here are the drives as listed in the above output:
da0 at ncr0 bus 0 target 0 lun 0
da0: <SEAGATE ST318436LW 0010> Fixed Direct Access SCSI-3 device
da0: 20.000MB/s transfers (10.000MHz, offset 8, 16bit), Tagged
Queueing Enabled
da0: 17522MB (35885168 512 byte sectors: 255H 63S/T 2233C)
da1 at ncr0 bus 0 target 1 lun 0
da1: <SEAGATE ST318436LW 0010> Fixed Direct Access SCSI-3 device
da1: 20.000MB/s transfers (10.000MHz, offset 8, 16bit), Tagged
Queueing Enabled
da1: 17522MB (35885168 512 byte sectors: 255H 63S/T 2233C)
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Blanking a rewriteable CD
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| In this section, I will blank out a rewritable CD. This is a CD which can be
written to many times. It is different from a CDR which can be written to only once.
It takes longer to write a rewritable CD than it does to write a single-write CD. But
first, I tried a dummy session, which would then eject the tray at the end:
# cdrecord -dummy -eject blank=all dev=1,5,0
And presto, whiz-bang, the CD was ejected! Woo hoo!
My next task as to actually blank that CD out. You don't have to do this, but I
wanted to. Warning: blanking all of a CD takes time. This one took about 20
minutes (remember you may want to should adjust speed to suit your CD drive):
# cdrecord -eject speed=4 blank=all dev=1,5,0
Cdrecord 1.9 (i386-unknown-freebsd4.2)
Copyright (C) 1995-2000 Jörg Schilling
scsidev: '1,5,0'
scsibus: 1 target: 5 lun: 0
Using libscg version 'schily-0.1'
Device type : Removable CD-ROM
Version : 2
Response Format: 2
Capabilities : SYNC LINKED
Vendor_info : 'PLEXTOR '
Identifikation : 'CD-R PX-W124TS'
Revision : '1.05'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
Driver flags : SWABAUDIO
cdrecord: Drive needs to reload the media to return to proper status
Starting to write CD/DVD at speed 4 in write mode for single session
Last chance to quit, starting real write in 1 seconds.
That took about 10 minutes or so.
You can see where it reloaded the media. That's when it ejected the tray and
pulled it back in. Be careful not to block the CD tray (i.e. keep your coffee cup
away from the tray!). |
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Creating an image
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In order to write data to a CD, you first need to create an ISO image. This can
be done with mkisofs. In my example, we'll work from the /home/recording
directory. In this directory, I created a subdirectory called files. Here is
what it contains:
# ls -l files
total 5280
-rw-r--r-- 1 root wheel 2174400 Dec 12 10:56 freebsddiary.tif
-rw-r--r-- 1 root wheel 2239494 Dec 12 10:57 freshports.tgz
-rw-r--r-- 1 root wheel 956533 Dec 12 10:56 mycvs.tgz
From these files, I will create an ISO image:
# mkisofs -J -L -R -o cdimage.raw files
Total translation table size: 0
Total rockridge attributes bytes: 471
Total directory bytes: 0
Path table size(bytes): 10
Max brk space used a164
2649 extents written (5 Mb)
Thanks to mikem for helping me with the following options. I use these on each CD
I write. Note: if you don't use the -J option, you may have problems if
you use the CD under Windows (I know, my first CDR didn't use this option).
-J Generate Joliet directory records in addition to
regular iso9660 file names. This is primarily use-
ful when the discs are to be used on Windows-NT or
Windows-95 machines. The Joliet filenames are
specified in Unicode and each path component can be
up to 64 Unicode characters long.
-L Allow ISO9660 filenames to begin with a period.
Usually, a leading dot is replaced with an under-
score in order to maintain MS-DOS compatibility.
This violates the ISO9660 standard, but it happens
to work on many systems. Use with caution.
-P publisher_id
Specifies a text string that will be written into
the volume header. This should describe the pub-
lisher of the CDROM, usually with a mailing address
and phone number. There is space on the disc for
128 characters of information. This parameter can
also be set in the file .mkisofsrc with PUBL=. If
specified in both places, the command line version
is used.
-p preparer_id
Specifies a text string that will be written into
the volume header. This should describe the pre-
parer of the CDROM, usually with a mailing address
and phone number. There is space on the disc for
128 characters of information. This parameter can
also be set in the file .mkisofsrc with PREP=. If
specified in both places, the command line version
is used.
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Things I saw but didn't worry about
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In other testing, I used some long file names. I had installed samba on my box and used that to copy files from my NT box onto the
box containing my CDRW. Then I started to make images for burning a backup CD.
That's when I encountered messages like this:
$ mkisofs -J -L -R -o racing.raw racing/
Using KARAP000 for racing/db/Karapoti (Karapoti2000)
Using KARAP001 for racing/db/Karapoti2000 (Karapoti98)
At first I was worried. I thought cdrecord was converting long file
names to short file names OUCH! But then I mounted the ISO image and inspected
the files. Everything appeared normal. Good news!
I started reading man mkisofs where I discovered translation tables.
When long file or directory names are used, the ISO image also contains short names (as in
DOS names which allow only 8 characters before the . and 3 characters after it). I
now believe the above messages are just notification of the short file names cdrecord
will use. |
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Testing the CD image
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The easiest way to test an image is to mount it. And oddly enough, I wrote about
mounting an ISO image more than two months ago. Here's
how to do it:
vnconfig /dev/vn0c ./cdimage.raw
mount -t cd9660 /dev/vn0c /mnt
Now you can list the contents of the image from /mnt:
# ls -lR /mnt
total 5244
-rw-r--r-- 1 root wheel 2174400 Dec 12 10:56 freebsddiary.tif
-rw-r--r-- 1 root wheel 2239494 Dec 12 10:57 freshports.tgz
-rw-r--r-- 1 root wheel 956533 Dec 12 10:56 mycvs.tgz
As you can see, this is exactly the same as what we had originally. I guess you
could also do a diff, but I think that's of little use here. It's a
direct disk to disk copy. But I did one anyway. I don't recommend you do it:
# diff /mnt/ files/
#
Remember to unmount the ISO image:
umount /mnt
vnconfig -u /dev/vn0c
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Burning the CDRW
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| This process will allow you to burn one session on a CD. If you later wish to
add additional data, you need a multi-session CD. See cdrecord
- writing multiple sessions for that information. For this exercise, I'm going to
use a rewriteable CD. That is why I'm using speed=4. Now it's time
to burn the image. This is the command I used (remember you may want to should
adjust speed to suit your CD drive):
# cdrecord -eject speed=4 dev=1,5,0 cdimage.raw
Cdrecord 1.9 (i386-unknown-freebsd4.2)
Copyright (C) 1995-2000 Jörg Schilling
scsidev: '1,5,0'
scsibus: 1 target: 5 lun: 0
Using libscg version 'schily-0.1'
Device type : Removable CD-ROM
Version : 2
Response Format: 2
Capabilities : SYNC LINKED
Vendor_info : 'PLEXTOR '
Identifikation : 'CD-R PX-W124TS'
Revision : '1.05'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
Driver flags : SWABAUDIO
Starting to write CD/DVD at speed 4 in write mode for single session
Last chance to quit, starting real write in 1 seconds.
Track 01: Total bytes read/written: 5425152/5425152 (2649 sectors).
The above command took about 20 seconds.
Now let's have a look at the results:
# mount /cdrom
# ls -l /cdrom
total 5244
-rw-r--r-- 1 root wheel 2174400 Dec 12 10:56 freebsddiary.tif
-rw-r--r-- 1 root wheel 2239494 Dec 12 10:57 freshports.tgz
-rw-r--r-- 1 root wheel 956533 Dec 12 10:56 mycvs.tgz
Well, there ya go! That's the results of the burn. And just to make sure
it's correct:
mount /cdrom
diff /cdrom files/
umount /cdrom
No differences! And that's a good thing.
Note that the above mount method relies on the following entry in /etc/fstab:
/dev/cd0a /cdrom cd9660 ro,noauto 0 0
Without such an entry, you can mount your cdrom with this command:
mount -t cd9660 -o ro /dev/cd0a /cdrom
But if you see this error:
cd9660: Device not configured
...the first thing to check is that there is a disk in the drive and that the tray has
not been ejected. This got me!
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Burning the first CDR
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| This process will allow you to burn one session on a CDR. If you later wish to
add additional data, you need a multi-session CD. See cdrecord
- writing multiple sessions for that information. After trying a CDRW, it was time
to burn a CD. If I fail with this, I'll have a coaster (for those unfamiliar with
the term, a coaster is something upon which you place your drink to avoid staining fine
furniture). Notice that I'm now using speed=12 (remember you may want to
should adjust speed to suit your CD drive).
# cdrecord -eject speed=12 dev=1,5,0 racing.raw
Cdrecord 1.9 (i386-unknown-freebsd4.2)
Copyright (C) 1995-2000 Jörg Schilling
scsidev: '1,5,0'
scsibus: 1 target: 5 lun: 0
Using libscg version 'schily-0.1'
Device type : Removable CD-ROM
Version : 2
Response Format: 2
Capabilities : SYNC LINKED
Vendor_info : 'PLEXTOR '
Identifikation : 'CD-R PX-W124TS'
Revision : '1.05'
Device seems to be: Generic mmc CD-RW.
Using generic SCSI-3/mmc CD-R driver (mmc_cdr).
Driver flags : SWABAUDIO
Starting to write CD/DVD at speed 12 in write mode for single
session.
Last chance to quit, starting real write in 1 seconds.
Track 01: Total bytes read/written: 653717504/653717504 (319198
sectors).
And that worked just fine! I did a diff:
mount /cdrom
diff -r /cdrom files
umount /cdrom
No errors! It's not a coaster! |
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Label it
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Philip Hallstrom wrote in to tell us about labelling the CDs. I had tried
to do this and failed. Here's what you do:
I just read you article on cdrecord and noticed that you don't use -V flag to mkisofs.
If you do something like:
mkisofs -V "MYLABEL" ....
then when you put the CD into a mac/windows box (I know I know, but it happens) it will
show up as "MYLABEL" which can be nice...
-philip
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Creating an ISO from a CD
21 September 2001
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If you want to create an ISO from a CD, here's how I did it (my thanks to Greg Lehey for this
solution as posted to the FreeBSD -questions mailing list):
Data on CDs is written in blocks of 2 kB. By default dd reads 512
bytes at a time, and the CD driver doesn't support this. It would
work if you use bs=2k. For the sake of efficiency, however, you
should select a larger block size, say 64 kB:
dd if=/dev/cd0a of=/home/disc.iso bs=64k
So I tried it:
# dd if=/dev/cd0a of=/home/disc.iso bs=64k
9428+1 records in
9428+1 records out
617930752 bytes transferred in 180.846213 secs (3416885 bytes/sec)
Then I verified that I could mount that ISO:
# vnconfig /dev/vn0c /home/disc.iso
# mount -t cd9660 /dev/vn0c /mnt
# ls /mnt
AUTORUN.INF Manual Readme.doc Sound Files
DXMedia Multimedia Tutorials STUDIO.ICO pinpctv.inf
DirectX OEM Samples welcome.exe
Driver PCTV.CAB Setup
# umount /mnt
# vnconfig -u /dev/vn0c
That looks good enough to me!
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