o que determina a capacidade de gravação excessiva do CD-R?

Question

Eu tinha uma imagem ISO de 733MiB que tentei gravar em um CD-R. Eu tinha dois discos CD-R de diferentes fabricantes. Com o primeiro disco CD-R (TDK), o processo de gravação falhou, mas usando o segundo CD-R (EMTEC), ele foi bem-sucedido. O comando usado para gravação foi wodim -v speed=1 dev='/dev/scd0' -sao -overburn /home/martin/Downloads/linux.iso

Tentativa malsucedida:

root@T42:~# ls -lh /home/martin/Downloads/linux.iso
-rw-r--r-- 1 martin martin 733M Feb  7 19:30 /home/martin/Downloads/linux.iso
root@T42:~# wodim -v speed=1 dev='/dev/scd0' -sao -overburn /home/martin/Downloads/linux.iso
TOC Type: 1 = CD-ROM
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    : 'HL-DT-ST'
Identification : 'DVDRAM GSA-4083N'
Revision       : '1.00'
Device seems to be: Generic mmc2 DVD-R/DVD-RW.
Current: 0x0009 (CD-R)
Profile: 0x0012 (DVD-RAM) 
Profile: 0x0011 (DVD-R sequential recording) 
Profile: 0x0015 (DVD-R/DL sequential recording) 
Profile: 0x0016 (DVD-R/DL layer jump recording) 
Profile: 0x0014 (DVD-RW sequential recording) 
Profile: 0x0013 (DVD-RW restricted overwrite) 
Profile: 0x001A (DVD+RW) 
Profile: 0x001B (DVD+R) 
Profile: 0x002B (DVD+R/DL) 
Profile: 0x0010 (DVD-ROM) 
Profile: 0x0009 (CD-R) (current)
Profile: 0x000A (CD-RW) 
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 
Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
Drive buf size : 1053696 = 1029 KB
Beginning DMA speed test. Set CDR_NODMATEST environment variable if device
communication breaks or freezes immediately after that.
Drive DMA Speed: 15251 kB/s 86x CD 11x DVD
FIFO size      : 12582912 = 12288 KB
Track 01: data   732 MB        
Total size:      840 MB (83:17.54) = 374816 sectors
Lout start:      841 MB (83:19/41) = 374816 sectors
Current Secsize: 2048
ATIP info from disk:
  Indicated writing power: 5
  Is not unrestricted
  Is not erasable
  Disk sub type: Medium Type B, low Beta category (B-) (4)
  ATIP start of lead in:  -12369 (97:17/06)
  ATIP start of lead out: 359849 (79:59/74)
Disk type:    Short strategy type (Phthalocyanine or similar)
Manuf. index: 69
Manufacturer: Moser Baer India Limited
Manufacturer is guessed because of the orange forum embargo.
The orange forum likes to get money for recent information.
The information for this media may not be correct.
Blocks total: 359849 Blocks current: 359849 Blocks remaining: -14967
wodim: WARNING: Data may not fit on current disk.
wodim: Notice: Overburning active. Trying to write more than the official disk capacity.
Speed set to 1764 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:  724 of  732 MB written (fifo 100%) [buf 100%]  10.7x.Errno: 5 (Input/output error), write_g1 scsi sendcmd: no error
CDB:  2A 00 00 05 A9 9D 00 00 1F 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 03 00 00 00 00 0A 3C 30 00 80 02 00 00 00
Sense Key: 0x3 Medium Error, Segment 0
Sense Code: 0x02 Qual 0x00 (no seek complete) Fru 0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 26.366s timeout 200s

write track data: error after 760014848 bytes
wodim: A write error occured.
wodim: Please properly read the error message above.
Writing  time:  549.691s
Average write speed   9.1x.
Min drive buffer fill was 99%
Fixating...
Fixating time:    0.183s
wodim: fifo had 12091 puts and 11972 gets.
wodim: fifo was 0 times empty and 11841 times full, min fill was 96%.
root@T42:~# 

Tentativa bem sucedida:

root@T42:~# wodim -v speed=1 dev='/dev/scd0' -sao -overburn /home/martin/Downloads/linux.iso
    TOC Type: 1 = CD-ROM
    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    : 'HL-DT-ST'
    Identification : 'DVDRAM GSA-4083N'
    Revision       : '1.00'
    Device seems to be: Generic mmc2 DVD-R/DVD-RW.
    Current: 0x0009 (CD-R)
    Profile: 0x0012 (DVD-RAM) 
    Profile: 0x0011 (DVD-R sequential recording) 
    Profile: 0x0015 (DVD-R/DL sequential recording) 
    Profile: 0x0016 (DVD-R/DL layer jump recording) 
    Profile: 0x0014 (DVD-RW sequential recording) 
    Profile: 0x0013 (DVD-RW restricted overwrite) 
    Profile: 0x001A (DVD+RW) 
    Profile: 0x001B (DVD+R) 
    Profile: 0x002B (DVD+R/DL) 
    Profile: 0x0010 (DVD-ROM) 
    Profile: 0x0009 (CD-R) (current)
    Profile: 0x000A (CD-RW) 
    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 
    Supported modes: TAO PACKET SAO SAO/R96P SAO/R96R RAW/R16 RAW/R96P RAW/R96R
    Drive buf size : 1053696 = 1029 KB
    Beginning DMA speed test. Set CDR_NODMATEST environment variable if device
    communication breaks or freezes immediately after that.
    Drive DMA Speed: 15143 kB/s 86x CD 10x DVD
    FIFO size      : 12582912 = 12288 KB
    Track 01: data   732 MB        
    Total size:      840 MB (83:17.54) = 374816 sectors
    Lout start:      841 MB (83:19/41) = 374816 sectors
    Current Secsize: 2048
    ATIP info from disk:
      Indicated writing power: 5
      Is not unrestricted
      Is not erasable
      Disk sub type: Medium Type A, high Beta category (A+) (3)
      ATIP start of lead in:  -11634 (97:26/66)
      ATIP start of lead out: 359846 (79:59/71)
    Disk type:    Short strategy type (Phthalocyanine or similar)
    Manuf. index: 3
    Manufacturer: CMC Magnetics Corporation
    Blocks total: 359846 Blocks current: 359846 Blocks remaining: -14970
    wodim: WARNING: Data may not fit on current disk.
    wodim: Notice: Overburning active. Trying to write more than the official disk capacity.
    Speed set to 1764 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:  732 of  732 MB written (fifo 100%) [buf  99%]  10.6x.
    Track 01: Total bytes read/written: 767623168/767623168 (374816 sectors).
    Writing  time:  520.286s
    Average write speed   9.6x.
    Min drive buffer fill was 99%
    Fixating...
    Fixating time:    4.733s
    wodim: fifo had 12091 puts and 12091 gets.
    wodim: fifo was 0 times empty and 11889 times full, min fill was 96%.
    root@T42:~#

A capacidade de gravação excessiva depende exclusivamente do tamanho do CD-R / CD-RW? Além disso, quaisquer ideias que a "categoria Beta baixa (B-) (4)" e "alta categoria Beta (A +) (3)" significa em CD-R Seção de informações da ATIP?

    

Answer 1

O tamanho original do armazenamento de dados do CD foi de 650 MiB; esses também são chamados de CDs de 74 minutos, já que é a quantidade de dados de áudio que você pode obter no mesmo espaço. Depois que os CD-Rs começaram a se tornar disponíveis, você começou a ver CD-Rs de 700 MiB (ou 80 minutos). A maioria dos CD-Rs vendidos atualmente é desse tipo mais recente.

Eu nunca vi um CD-R capaz de armazenar 733 MiB e A primeira página de resultados da Amazon para "CD-R" não é tão grande assim.

Pode ser apenas uma sorte que permitiu que a imagem fosse gravada. Ou, pode não ter queimado corretamente depois de tudo. Se o seu instalador do sistema operacional tiver um recurso de verificação de mídia, você deve definitivamente usá-lo na primeira vez que instalar a partir desse disco com excesso de gravação.

Essa imagem pode não ser destinada a CD-Rs. O formato de CD ISO está se tornando popular para imagens de chave USB. Existem ferramentas como UNetbootin para este propósito.