Re: [gentoo-user] Booting minimal installer ISO on rx4640 and rx2660 fails

[Frank Scheiner]

Mick and mad.scientist.at.large - thanks for your suggestions so far.

On 08/17/2017 12:14 PM, mad.scientist.at.large@××××××××.com wrote:
> Last time i used it, Brasero didn't have an option to verify the just
> burned disk, you likely have a bad burn.

The Brasero version as used by me has an option to verify the burned 
disk, which was active and succeeded for the first one burned with the 
DVDRW drive (the minimal installer from 20170810) in my docking station.

But now checking the contents by using dd and sha512sum (`dd if=/dev/sr0 
bs=2048 count=$(( $ISO_FILE_SIZE_IN_BYTES / 2048)) | sha512sum`) indeed 
showed differences and dd complained about not being able to copy the 
last block. I then also checked the burned CDROMs with the cdck tool and 
this also complained about unreadable blocks at the end of the CDROMs.

Checking one of my older CDROMs, the last blocks seem to be foobar 
there, too. :-(

Very strange, as I didn't have problems in the past with CDROMs burned 
on this DVDRW drive or with an external USB-DVDRW.

I now changed to another machine with a "non-laptop" DVDRW drive (an HP 
DVD-RAM GH40L) and burned the older ISO to a CDROM with the wodim tool 
and using DAO/SAO mode:

```
# time wodim -dao -v dev=/dev/sg0 -eject 
iso/gentoo/ia64/install-ia64-minimal-20170627.iso
TOC Type: 1 = CD-ROM
scsidev: '/dev/sg0'
devname: '/dev/sg0'
scsibus: -2 target: -2 lun: -2
Linux sg driver version: 3.5.34
Wodim version: 1.1.11
SCSI buffer size: 64512
Device type    : Removable CD-ROM
Version        : 5
Response Format: 2
Capabilities   :
Vendor_info    : 'hp      '
Identification : 'DVD-RAM GH40L   '
Revision       : 'RB12'
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 : 1016064 = 992 KB
Beginning DMA speed test. Set CDR_NODMATEST environment variable if device
communication breaks or freezes immediately after that.
Drive DMA Speed: 16047 kB/s 91x CD 11x DVD
FIFO size      : 12582912 = 12288 KB
Track 01: data   168 MB
Total size:      193 MB (19:10.54) = 86291 sectors
Lout start:      193 MB (19:12/41) = 86291 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: 273558
Speed set to 7057 KB/s
Starting to write CD/DVD at speed  40.0 in real SAO mode for single session.
Last chance to quit, starting real write in    1 seconds.
    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:  168 of  168 MB written (fifo 100%) [buf  96%]  27.0x.
Track 01: Total bytes read/written: 176723968/176723968 (86291 sectors).
Writing  time:   68.732s
Average write speed  16.8x.
Min drive buffer fill was 92%
Fixating...
Fixating time:    3.865s
wodim: fifo had 2784 puts and 2784 gets.
wodim: fifo was 0 times empty and 2361 times full, min fill was 95%.

real	1m24.320s
user	0m0.044s
sys	0m0.596s

# cdck -t -d /dev/sr0

NB! For disks written with some burners cdck might
     report about unreadable sectors at the end of the disk.
     In such cases you can just ignore those warnings.

Reading sectors 1-86291
86288 ok

CD overall:
    Sectors total: 86291:
    Good sectors: 86291:
    Bad sectors (incl. with poor timing): 0
CD timings:
    Minimal = 1 usec (0.000001s)
    Maximal = 49935 usec (0.049935s)
    Average = 614 usec (0.000614s)

Conclusion:
    Excellent disc!

# dd if=/dev/sr0 bs=2048 count=86291 of=file.iso
86291+0 records in
86291+0 records out
176723968 bytes (177 MB) copied, 54.9074 s, 3.2 MB/s

# sha512sum file.iso install-ia64-minimal-20170627.iso
7e21de1c31fd633466f9ffac54f9a01e64cd6cb461ef691a110453e1ecfba06fa6d736189594ffeb0a41b29d8297d869f4e440e6b75287311d0b36f9d9f92e40 
  file.iso
7e21de1c31fd633466f9ffac54f9a01e64cd6cb461ef691a110453e1ecfba06fa6d736189594ffeb0a41b29d8297d869f4e440e6b75287311d0b36f9d9f92e40 
  install-ia64-minimal-20170627.iso
```

This time the burned CDROM seems to be fully OK (including the last 
blocks), but...

...it still doesn't work and gives the same symptoms I already described 
(just tested in my rx4640).

> Dvd burns frequently go wrong, with my current media/burner they fail
> 5-10% of the time so far and that's typical in my experiance (though the
> age of my hardware is doubtless also part of such issues).

I can confirm these high error rates for DVDROMs from my past 
experience, but I burned CDROMs and hence assumed none of these 
problems. But apparently that was wrong to assume. :-/