UNIX for Dummies Questions & Answers

I'm new to all this cdrecord and I'm struggling trying to create backups on a DVD-RW disk using a NEC DVD writer that supports PACKET & SAO modes.

I've created two cd images by:
mkisofs -r -J -l -L -o /file1.iso /mnt
mkisofs -r -J -l -L -o /file2.iso /mnt

Then burned the first image to the DVD-RW:
cdrecord -v -sao -eject -multi /file1.iso

The files are visible & readable on this server and also in Windows File Explorer on an XP based PC.

I then try the second burn:
cdrecord -v -sao -eject -multi /file2.iso

when I get a reference to "trying to clear drive status" the dvd ejects and the command fails.

If I re-insert the dvd and:
cdrecord -msinfo

this fails with:
cdrecord: drive needs to reload the media to return to proper status
WARNING: Phys disk size 4989 differs from rzone size 0! Prerecorded disk?
WARNING: Phys start: 196608 Phys end 201596
0,0

If I try to:
cdrecord -blank=all

this works correctly and I can re-write the first track to the same dvd again!

So what am I missing?

I'm attempting to use the DVD-RW for a daily back-up of files from within SCO Openserver 6, so if there's a simpler way of doing it or a script could be used I'd appreciate any help!

Thanks in advance!

Further update!
Following the SCO notes from their knowledge base I have a slightly different snag - the bold sections are console feedback! - still hopeful somebody can help me! Cheers!

For the following example it is assumed that you want to create 3 different sessions on a CD.

1. session = /opt/
2. session = /u/
3. session = /var/

Run "cdrecord -scanbus" to determine the device settings of your CD/DVD burner. Exact output:

Cdrecord-ProDVD-Clone 2.01a27 (i386-pc-sco3.2v5.0.7)
Copyright (C) 1995-2004 J����rg Schilling
Using libscg version 'schily-0.8'.
scsibus1:
1,0,0 100) 'TSSTcorp ' 'CD/DVDW SHS182D ' 'SB04'
Removable CD-ROM
1,1,0 101) 'TEAC ' 'CD-540E ' '1.0A'
Removable CD-ROM
1,2,0 102) *
1,3,0 103) *
1,4,0 104) *
1,5,0 105) *
1,6,0 106) *
1,7,0 107) *

The CD burner is at 1,0,0.

Now make sure that you have an empty CD. You can blank a
RW-CD by issuing the command "cdrecord dev=1,0,0
-blank=fast"

Now follow these steps:
1. mkisofs -o /session1.iso -l -r -J -T /opt/
This will create the image /session1.iso

2. cdrecord dev=1,0,0 –sao -multi /session1.iso
This will burn the first session on the CD

3. cdrecord -msinfo dev=1,0,0
This will print out 2 numbers (X,Y). These two numbers are
required in step 4

0,0

4. mkisofs -o /session2.iso -l -r -J -C X,Y -M /dev/cd0 /u/
Substitute X and Y with the output of step 3

Rock Ridge signatures found
mkisofs: Error: ‘/rr_moved/html’ and ‘/rr_moved/html’ have the same Rock (missing text) ame ‘html’ .
(The screen scrolls rapidly indicating that there are many files with a similar problem)
mkisofs: Unable to sort directory /rr_moved

5. cdrecord dev=1,0,0 –sao -multi /session2.iso
This will burn the second session on the CD

6. cdrecord -msinfo dev=1,0,0
This will print out 2 numbers (X,Y). These two number are required in step 7

7. mkisofs -o /session3.iso -l -r -J -C X,Y -M /dev/cd0 /var/
Substitute X and Y with the output of step 6

8. cdrecord dev=1,0,0 –sao /session3.iso
This will burn the third session on the CD. Note that this will close the CD because the option "-multi" is missing.


Mount the CD with "mount -r /dev/cd0 /mnt"

NOTES:
At this time multi-session support is only available for
CD and not for DVD.