[conspire] cd burning giving slight errors

Tue Nov 8 07:39:34 PST 2011

That is interesting because I'd like to think that reads would be even
more immune; I suppose It's a leap of faith that I assume the hardware
driver or firmware would dynamically change to a slower speed and retry
failed reads during normal I/O, as opposed to reading at a pre-specified
speed.

Thanks for the update!
_S

On Mon, 2011-11-07 at 20:52 -0800, Peter Knaggs wrote: 
> Hi Sean,
> 
> Perhaps the problem isn't with the "writing" but with
> the "reading": the readom page gave me a clue, when
> they say "Using a lower speed may increase the readability of a CD or DVD.".
> 
> So I'm giving that a try now, looks good so far.
> 
> What tipped me off was, I tried reading the same burned CD twice
> in a row at the default (max) speed, and got two slightly different outputs.
> 
> So then I thought, perhaps there's excessive vibration
> or something causing read errors when the CD motor
> spins so fast as it's doing the sequential read.
> 
> So perhaps my burns have been OK all along,
> it's just the verification step was reading the CD too fast,
> and messing up the read!
> 
> So now I'm using this command to read "slowly and quietly".
> 
> readom speed=1 -v dev=/dev/scd0 f=./testing_read
> 
> Thanks for your help!
> 
> I was going crazy from puzzlement... :)
> 
> But as they say, “Once you eliminate the impossible,
> whatever remains, no matter how improbable,
> must be the truth.”
> 
> I'll try some reads at various higher speeds, to see when the
> errors start happening, but at least now I know it's a "hardware
> problem", or rather a "newbie misusing the hardware problem".
> 
> Cheers,
> Peter.
> 
> On Mon, Nov 7, 2011 at 11:50 AM, Sean <sean.channel at pacbell.net> wrote:
> > Indeed: DAO will add fewer control bits/blocks than TAO. If you can make
> > -raw work, I suspect you may have a totally clean checksum.
> >
> > Funny: I was just looking into PenLUG (seems pretty quiet) before I saw
> > your message on conspire.
> >
> > Best luck,
> > _S
> >
> > On Mon, 2011-11-07 at 01:16 -0800, Peter Knaggs wrote:
> >> Hi Sean,
> >>
> >> Thanks for taking a look. I added the -dao flag,
> >> still get errors writing (less, though, only four wrong bytes
> >> this time).
> >>
> >> Output looks as follows.
> >>
> >> I'm using a CD-RW media now, to avoid making
> >> so many coasters.
> >>
> >> The only thing I can think of that I changed on this
> >> system was adding some more memory.
> >> I've run the memtest and it passed OK,
> >> and I've done repeated parallel kernel builds
> >> which ran fine, so I guess the memory is OK.
> >>
> >> I'm debugging a problem in Inkscape at the
> >> moment, quite bizarre behavior, but at least I get
> >> to practice debugging a C++ program for a change.
> >>   https://bugs.launchpad.net/ubuntu/+source/inkscape/+bug/790130
> >>
> >> Cheers,
> >> Peter.
> >>
> >> $ wodim speed=1 -dao -v dev=/dev/scd0 -data ubuntu-11.10-desktop-amd64.iso
> >> TOC Type: 1 = CD-ROM
> >> wodim: Operation not permitted. Warning: Cannot raise RLIMIT_MEMLOCK limits.
> >> scsidev: '/dev/scd0'
> >> devname: '/dev/scd0'
> >> scsibus: -2 target: -2 lun: -2
> >> Linux sg driver version: 3.5.27
> >> Wodim version: 1.1.11
> >> SCSI buffer size: 64512
> >> Device type    : Removable CD-ROM
> >> Version        : 5
> >> Response Format: 2
> >> Capabilities   :
> >> Vendor_info    : 'ATAPI   '
> >> Identification : 'iHAS222   8     '
> >> Revision       : '4L01'
> >> Device seems to be: Generic mmc2 DVD-R/DVD-RW.
> >> Current: 0x000A (CD-RW)
> >> Profile: 0x002B (DVD+R/DL)
> >> Profile: 0x001B (DVD+R)
> >> Profile: 0x001A (DVD+RW)
> >> Profile: 0x0016 (DVD-R/DL layer jump recording)
> >> Profile: 0x0015 (DVD-R/DL sequential recording)
> >> Profile: 0x0014 (DVD-RW sequential recording)
> >> Profile: 0x0013 (DVD-RW restricted overwrite)
> >> Profile: 0x0012 (DVD-RAM)
> >> Profile: 0x0011 (DVD-R sequential recording)
> >> Profile: 0x0010 (DVD-ROM)
> >> Profile: 0x000A (CD-RW) (current)
> >> Profile: 0x0009 (CD-R)
> >> Profile: 0x0008 (CD-ROM)
> >> Profile: 0x0002 (Removable disk)
> >> Using generic SCSI-3/mmc   CD-R/CD-RW driver (mmc_cdr).
> >> Driver flags   : MMC-3 SWABAUDIO BURNFREE FORCESPEED
> >> Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
> >> Drive buf size : 1867008 = 1823 KB
> >> Beginning DMA speed test. Set CDR_NODMATEST environment variable if device
> >> communication breaks or freezes immediately after that.
> >> FIFO size      : 12582912 = 12288 KB
> >> Track 01: data   697 MB
> >> Total size:      800 MB (79:20.18) = 357014 sectors
> >> Lout start:      801 MB (79:22/14) = 357014 sectors
> >> Current Secsize: 2048
> >> ATIP info from disk:
> >>   Indicated writing power: 3
> >>   Reference speed: 6
> >>   Is not unrestricted
> >>   Is erasable
> >>   Disk sub type: High speed Rewritable (CAV) media (1)
> >>   ATIP start of lead in:  -11596 (97:27/29)
> >>   ATIP start of lead out: 359849 (79:59/74)
> >>   1T speed low:  4 1T speed high: 10
> >>   2T speed low:  4 2T speed high:  0 (reserved val  6)
> >>   power mult factor: 1 5
> >>   recommended erase/write power: 4
> >>   A1 values: 24 1A C8
> >>   A2 values: 26 B2 4A
> >> Disk type:    Phase change
> >> Manuf. index: 20
> >> Manufacturer: Princo Corporation
> >> Blocks total: 359849 Blocks current: 359849 Blocks remaining: 2835
> >> Forcespeed is OFF.
> >> Speed set to 1765 KB/s
> >> Starting to write CD/DVD at speed  10.0 in real SAO mode for single session.
> >> Last chance to quit, starting real write in    0 seconds. Operation starts.
> >> Waiting for reader process to fill input buffer ... input buffer ready.
> >> Performing OPC...
> >> Sending CUE sheet...
> >> Writing pregap for track 1 at -150
> >> Starting new track at sector: 0
> >> Track 01:  697 of  697 MB written (fifo 100%) [buf 100%]  10.6x.
> >> Track 01: Total bytes read/written: 731164672/731164672 (357014 sectors).
> >> Writing  time:  488.544s
> >> Average write speed   9.7x.
> >> Min drive buffer fill was 99%
> >> Fixating...
> >> Fixating time:   15.180s
> >> BURN-Free was never needed.
> >> wodim: fifo had 11517 puts and 11517 gets.
> >> wodim: fifo was 0 times empty and 11312 times full, min fill was 95%.
> >>
> >>
> >>
> >>
> >> $ readom -v dev=/dev/scd0 f=./testing_read
> >> scsidev: '/dev/scd0'
> >> devname: '/dev/scd0'
> >> scsibus: -2 target: -2 lun: -2
> >> Linux sg driver version: 3.5.27
> >> Read  speed:  7057 kB/s (CD  40x, DVD  5x).
> >> Write speed:  1765 kB/s (CD  10x, DVD  1x).
> >> Capacity: 357014 Blocks = 714028 kBytes = 697 MBytes = 731 prMB
> >> Sectorsize: 2048 Bytes
> >> Copy from SCSI (2,0,0) disk to file './testing_read'
> >> end:    357014
> >> addr:   357014 cnt: 22
> >> Time total: 167.613sec
> >> Read 714028.00 kB at 4260.0 kB/sec.
> >>
> >>
> >>
> >>
> >> $ cmp -l testing_read ubuntu-11.10-desktop-amd64.iso
> >>  40983529  73  43
> >>  40983545 166 366
> >> 191329272  66  62
> >> 300276720 130 120
> >>
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> >
> >
> 
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