Mailinglist Archive: packet-writing (46 mails)

[Peter Osterlund <petero2@xxxxxxxxx>]

On 8 Jun 2002, ulrich mensfeld wrote:

> > I'm trying Peters advice with 2.4.19-pre4-patch, and will disable caching.
> > I'll write what happens when writing to a fresh formatted cdrw. Do you
> > have the same burner as i?
> 
> OK, here my experience:
> 
> i patched the kernel with this patch, and some things have changed. When
> writing to my burner, it's LED's are flickering in complete other mode.
> Also the recording speed (my other mail) seems to be higher. I've compiled
> the kernel without caching enabled.
> 
> But when rereading the written UDF-CDRW from my cdROM, i allways get
> errors on some files. I would say, about 1 of 100 files is corrupt.
> If i copy only some large files 1by1, all goes on. If i copy the whole  
> /usr/src/linux, errors are there.

I did a similar experiment with kernel 2.4.19-pre9 and packet-2.4.19-pre4.
I created an ext2 filesystem with block size 2048 on a CDRW disc. I
unpacked the 2.4.18 kernel tree to the CDRW disc, built the kernel, then
cleaned up with "make mrproper".

I then compared the tree on the CDRW with a tree on the hard disk, and 22
files (out of 10006) were corrupted. In all cases the corruption was
limited to a 2Kb block beginning either at offset 0x5800 or 0x6000 in the
file. In most cases the corrupted data looked like binary junk, but in a
few cases the corrupted data consisted of pieces from other kernel source
files.

So there seems to be something wrong in the pktcdvd code causing
corruption. (I doubt the ext2 filesystem is buggy and the udf filesystem
wasn't even used.)

-- 
Peter Osterlund - petero2@xxxxxxxxx
http://w1.894.telia.com/~u89404340