Why the cdrecord detect driver's buf szie is not the same as the driver?
 

Hello.everyone
When I used cdrecord to record discs ,I found the cdrecord detected writers' buf is wrong ,this writer buf value is 2M,but when I used it to record cdr,it appeared as below---there only 870KB.when I recorded dvdr,the vlue changed to 992KB,why it can't recorgnize its right value.If I want to use the writer right buf value--2M,how can I do ?

Best Regard
Hougaga

./cdrecord -v -dummy fs=16m dev=ATAPI:0,6,0 /tmp/cd driveropts=burnfree gracetime=3
./cdrecord: No write mode specified.
./cdrecord: Asuming -tao mode.
./cdrecord: Future versions of cdrecord may have different drive dependent defaults.
./cdrecord: Continuing in 5 seconds...
Cdrecord-ProDVD-Clone 2.01.01a19 (i686-pc-linux-gnu) Copyright (C) 1995-2006 J鰎g Schilling
TOC Type: 1 = CD-ROM
scsidev: 'ATAPI:0,6,0'
devname: 'ATAPI'
scsibus: 0 target: 6 lun: 0
Warning: Using ATA Packet interface.
Warning: The related Linux kernel interface code seems to be unmaintained.
Warning: There is absolutely NO DMA, operations thus are slow.
Using libscg version 'schily-0.8'.
Driveropts: 'burnfree'
SCSI buffer size: 64512
atapi: 0
Device type : Removable CD-ROM
Version : 0
Response Format: 2 Capabilities :
Vendor_info : 'SONY '
Identifikation : 'DVD RW AW-G170A '
Revision : '1.62'
Device seems to be: Generic mmc2 DVD-R/DVD-RW/DVD-RAM.
Current: CD-R
Profile: DVD+R/DL
Profile: DVD+R
Profile: DVD+RW
Profile: DVD-R/DL layer jump recording
Profile: DVD-R/DL sequential recording
Profile: DVD-RW sequential overwrite
Profile: DVD-RW restricted overwrite
Profile: DVD-RAM
Profile: DVD-R sequential recording
Profile: DVD-ROM
Profile: CD-RW
Profile: CD-R (current)
Profile: CD-ROM (current)
Profile: 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/R96R RAW/R96R
Drive buf size : 890880 = 870 KB
FIFO size : 16777216 = 16384 KB
Track 01: data 207 MB
Total size: 238 MB (23:36.26) = 106220 sectors
Lout start: 238 MB (23:38/20) = 106220 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: -11607 (97:27/18)
ATIP start of lead out: 359849 (79:59/74)
Disk type: Short strategy type (Phthalocyanine or similar)
Manuf. index: 18
Manufacturer: Plasmon Data systems Ltd.

Capacity Blklen/Sparesz. Type
0 2048 No Media Present or Unknown Capacity
Blocks total: 359849 Blocks current: 359849 Blocks remaining: 253629
Starting to write CD/DVD at speed 32 in dummy TAO mode for single session.
Last chance to quit, starting dummy write in 3 seconds.

I don't see a problem.
This says the size if 2048 kb (2 mb).
This says that as data enters the buffer, and leaves the buffer, the net size of used buffer is 870 kb.

In other words, you have enough buffer to support the operation. The overall size of the buffer, and the used amount, are not important, unless the buffers goes to 0 used. Then you will have gaps and skips in the recording. Keep a buffer large enough that it never goes to empty to avoid problems. Don't worry that the full buffer space isn't used at all times. Just don't let the buffer go to empty while writing.