Redhat Linux and Optical Drive

I've been asked to try to find out what's on an optical disk and extract what data is on it, big problem is I've got no info on what format the disk is in except that they believe it was created on a Linux system. I can't look at the disk in Unixware, XP just offers to format it for me.

Here's what I've got for starters:

Redhat Linux 9.1 (I've never used Linux before, although I've got a little experience with UnixWare - consider me a COMPLETE newb )
Plasmon DW260 optical drive (/dev/sg1 according to the device manager)

At the moment I can't even access the drive. Do I need to mount it? Linux tells me it's not a block device when I try to do that.

Is there a Linux command that'll tell me what file system is on the disk?

I'm due to report back on my findings in the next couple of days, so any offers of help would be much appreciated.

 

How do you try mounting it? I've no idea what an optical disk is, sounds like a CD to me .... Does "http://tldp.org/HOWTO/Optical-Disk-HOWTO.html" help? Usually you can just mount anything by doing:

mount /dev/sg1 /mnt

Sometimes you have to specify the filesystem when mounting, have you tried specifying ext2 or ext3? That is usually the FS for Linux...

 

Vlad, cheers for replying. I've been trying to mount it with:

'mount -t auto /dev/sg1 /mnt/optical' but I get a '/dev/sg1 is not a block device' error every time. I've worked through several of the filesystems other than auto, ext2, ext3 etc. but it's always the same.

I don't know if I need a special driver for it, I haven't got any documentation for it and searching the net hasn't got me anywhere looking for one. The GUI lists it as I said before, but it could just be picking it up from the SCSI card and not actually recognising it?

PS - It's just a big CD really, double sided and it holds about 2.6Gb of data.

Edit: Cheers for the link, I'll take a read.

 

Show me your output from 'dmesg', also try doing a 'cat /var/log/messages|grep sg1' What does that show? You may need to re-build your kernel, what does "ls -al /dev/scd*" show?



https://mail.fukt.bth.se/pipermail/crux/2003-April/000392.html

 

I'm getting somewhere now. The machine I'm using is standalone, and it took me a while to find mcopy to get the files onto my XP laptop

Looks like it's actually /dev/sda or /dev/sdb (depending on which side of the disk is loaded)

From dmesg:

Vendor: PLASMON Model: DW260 Rev: 221c
Type: Optical Device ANSI SCSI revision: 02
blk: queue c121fe14, I/O limit 4095Mb (mask 0xffffffff)
scsi0:A:0:0: Tagged Queuing enabled. Depth 253
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
Attached scsi removable disk sdb at scsi0, channel 0, id 6, lun 0
(scsi0:A:0): 160.000MB/s transfers (80.000MHz DT, offset 31, 16bit)
SCSI device sda: 17773524 512-byte hdwr sectors (9100 MB)
Partition check:
sda: sda1 sda2 sda3
(scsi0:A:6): 10.000MB/s transfers (10.000MHz, offset 14)
SCSI device sdb: 1273011 1024-byte hdwr sectors (1304 MB)
sdb: Write Protect is on
sdb:scsi0: ERROR on channel 0, id 6, lun 0, CDB: Read (10) 00 00 00 00 00 00 00 04 00
Info fld=0x2, Current sd08:10: sense key Medium Error
Additional sense indicates Data synchronization mark error
I/O error: dev 08:10, sector 4
scsi0: ERROR on channel 0, id 6, lun 0, CDB: Read (10) 00 00 00 00 03 00 00 01 00
Info fld=0x3, Current sd08:10: sense key Medium Error
Additional sense indicates Data synchronization mark error
I/O error: dev 08:10, sector 6
scsi0: ERROR on channel 0, id 6, lun 0, CDB: Read (10) 00 00 00 00 02 00 00 02 00
Info fld=0x2, Current sd08:10: sense key Medium Error
Additional sense indicates Data synchronization mark error
I/O error: dev 08:10, sector 4
scsi0: ERROR on channel 0, id 6, lun 0, CDB: Read (10) 00 00 00 00 03 00 00 01 00
Info fld=0x3, Current sd08:10: sense key Medium Error
Additional sense indicates Data synchronization mark error
I/O error: dev 08:10, sector 6
unable to read partition table
Journalled Block Device driver loaded

I ran a SCSI BIOS disk check and it's reporting errors everywhere, looks like the disk could be screwed up?

One worry, I want to check the SCSI settings, but there's no info on the case, I don't have a manual for it and I can't find one on the web. Everything's as it was when it was delivered so I'll leave it at that.

 

Word, I'm guessing sda and sdb don't mount either? Yeah those aer some weird errors, either it's the box or you need to recompile the kernel... I'd try recompiling either 2.4.22 or the latest 2.6 kernel with all options compiled except maybe developer options... I'd try 2.6 first (without the optical disk in there, god knows wether it will go crazy or not ) and try to see if it works and if not try 2.4.22... You're really lucky because you generally don't have to screw with beta (2.5)... If those don't work then I do recommend beta though

 

Cheers for that, I'll have to do a bit more reading up before I do kernel builds. I'm at 2.4.20-8 I think.

For info, here's the whole dmesg output.

 

The problem is I believe Red Hat uses it's own custom Red Hat hacked up patches.... I'd still see if it compiles, I've never worked under RH...