Re: Low burning speed
Tomasz Kaptocz wrote:
> 181403648/4220336128 ( 4.3%) @6.0x, remaining 11:30 RBU 99.1% UBU 84.6%
> 209125376/4220336128 ( 5.0%) @6.0x, remaining 10:52 RBU 100.0% UBU 80.8%
> 232062976/4220336128 ( 5.5%) @5.0x, remaining 10:53 RBU 100.0% UBU 73.1%
> 241631232/4220336128 ( 5.7%) @2.1x, remaining 11:15 RBU 98.9% UBU 30.8%
> 256933888/4220336128 ( 6.1%) @3.3x, remaining 11:18 RBU 100.0% UBU 19.2%
The drive seems to be willing to run at the speed which
is announced for the first part of the media: 6.0x.
The fact that the drive buffer (UBU) after a short time
of burning has less than 20 % fill indicates that there
is a problem with data transfer from computer to drive.
Effective throughput seems to be about 4.3 MB/second.
This incident here looks quite strange:
> 1882193920/4220336128 (44.6%) @3.7x, remaining 8:10 RBU 100.0% UBU 26.9%
> 1883176960/4220336128 (44.6%) @0.2x, remaining 8:13 RBU 100.0% UBU 100.0%
> 1883176960/4220336128 (44.6%) @0.0x, remaining 8:17 RBU 100.0% UBU 100.0%
> 1886191616/4220336128 (44.7%) @0.7x, remaining 8:21 RBU 100.0% UBU 15.4%
Drive buffer is reported as full, but there is no
substantial data transfer for a short time.
This cannot be blamed on a bad throughput.
Maybe the drive buffer ran empty and the drive
decided to wait until it is at 100 % again.
Then it needed some time to speed up disc rotation
Would it work with better speed if you do not
burn the ISO image on the fly but first generate
it in a disk file and afterwards burn that file
to media ?
For simplicity you could omit the mkisofs run
and just create a dummy file of 4 GB:
dd if=/dev/zero of=/tmp/4gb_of_zeros bs=1M count=4096
(1 GB = count=1024 should suffice too.)
This file could be burned to media by various programs:
growisofs -use-the-force-luke -Z /dev/sr0=/tmp/4gb_of_zeros
cdrecord -v dev=/dev/sr0 /tmp/4gb_of_zeros
cdrskin -v dev=/dev/sr0 /tmp/4gb_of_zeros
Of course, the result will not be mountable but only
bear a lot of 0-bytes. One can verify success by
diff /dev/sr0 /tmp/4gb_of_zeros
which might report surplus bytes on /dev/sr0.
Have a nice day :)