On Friday 13 Mar 2015 22:24:32 Neil Bothwick wrote:
> On Fri, 13 Mar 2015 17:54:01 +0000 (UTC), Grant Edwards wrote:
> > IIRC, there are ebuilds for ddrescue, photorec, and testdisk.
> 
> There's also app-cdr/dvdisaster.

Thank you all.  dd and ddrescue don't work, because the block device is not 
recognised.  I had already tried this with not success.

dvddisaster requires to have created a file with error correction ("ecc") data 
in advance of the hardware failure, then use that to recover the lost bits.

readcd is great - thanks Joerg!  However, this is what I got in my first 
attempt:
=================================================================
$ readcd dev=1,0,0 -v
scsidev: '1,0,0'
scsibus: 1 target: 0 lun: 0
Linux sg driver version: 3.5.36
readcd: Input/output error. set cd speed: scsi sendcmd: no error
CDB:  BB 00 FF FF FF FF 00 00 00 00 00 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 02 00 00 00 00 0A 00 00 00 00 04 01 00 00
Sense Key: 0x2 Not Ready, Segment 0
Sense Code: 0x04 Qual 0x01 (logical unit is in process of becoming ready) Fru 
0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 0.042s timeout 40s
Read  speed: 11080 kB/s (CD  62x, DVD  8x, BD  2x).
Write speed:     0 kB/s (CD   0x, DVD  0x, BD  0x).
0:read 1:veri   2:erase   3:read buffer 4:cache 5:ovtime 6:cap
7:wne  8:floppy 9:verify 10:checkcmds  11:read disk 12:write disk
13:scsireset 14:seektest 15: readda 16: reada 17: c2err
18:readcd 19: lin 20: full toc
Enter selection: 0 (0 - 20)/<cr>:
0:read 1:veri   2:erase   3:read buffer 4:cache 5:ovtime 6:cap
7:wne  8:floppy 9:verify 10:checkcmds  11:read disk 12:write disk
13:scsireset 14:seektest 15: readda 16: reada 17: c2err
18:readcd 19: lin 20: full toc
Enter selection: 4 (0 - 20)/<cr>:5    <==Not sure if I entered the correct No.
Doing 1000 'TEST UNIT READY' operations.
Time total: 0.296sec
Doing 1000 'SEEK_G1 (0)' operations.
Time total: 418.463sec
0:read 1:veri   2:erase   3:read buffer 4:cache 5:ovtime 6:cap
7:wne  8:floppy 9:verify 10:checkcmds  11:read disk 12:write disk
13:scsireset 14:seektest 15: readda 16: reada 17: c2err
18:readcd 19: lin 20: full toc
Enter selection: 10 (0 - 20)/<cr>:
=================================================================


Here I tried different values, none of which produced anything until:
=================================================================
Enter selection: 10 (0 - 20)/<cr>:11
Capacity: 2295104 Blocks = 4590208 kBytes = 4482 MBytes = 4700 prMB
Sectorsize: 2048 Bytes
Ignore disk size? y
Copy from SCSI (1,0,0) disk to file
Enter filename [disk.out]: disk.out
Enter starting sector for copy: 0 (0 - 9999999)/<cr>:0
Enter number of sectors to copy: 10000000 (1 - 10000000)/<cr>:
Enter number of sectors per copy: 64 (1 - 64)/<cr>:
end:  10000000
readcd: Input/output error. read_g1: scsi sendcmd: no error
CDB:  28 00 00 00 00 00 00 00 40 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 04 00 00 00 00 0A 00 00 00 00 3E 02 00 00
Sense Key: 0x4 Hardware Error, Segment 0
Sense Code: 0x3E Qual 0x02 (timeout on logical unit) Fru 0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 10.414s timeout 40s
readcd: Input/output error. Cannot read source disk
readcd: Retrying from sector 0.
.~~-readcd: Input/output error. test unit ready: scsi sendcmd: no error
CDB:  00 00 00 00 00 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 02 00 00 00 00 0A 00 00 00 00 3A 00 00 00
Sense Key: 0x2 Not Ready, Segment 0
Sense Code: 0x3A Qual 0x00 (medium not present) Fru 0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 0.009s timeout 40s
~readcd: Input/output error. test unit ready: scsi sendcmd: no error
CDB:  00 00 00 00 00 00
status: 0x2 (CHECK CONDITION)
=================================================================


This repeated itself for a while, until:
=================================================================
readcd: Input/output error. Error on sector 0 not corrected. Total of 1 
errors.
readcd: Input/output error. read_g1: scsi sendcmd: no error
CDB:  28 00 00 00 00 00 00 00 01 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 02 00 00 00 00 0A 00 00 00 00 3A 00 00 00
Sense Key: 0x2 Not Ready, Segment 0
Sense Code: 0x3A Qual 0x00 (medium not present) Fru 0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 0.009s timeout 40s

Time total: 156.756sec
Read 0.00 kB at 0.0 kB/sec.
Max corected retry count was 0 (limited to 128).
The following 1 sector(s) could not be read correctly:
0
readcd: Input/output error. test unit ready: scsi sendcmd: no error
CDB:  00 00 00 00 00 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: 70 00 02 00 00 00 00 0A 00 00 00 00 3A 00 00 00
Sense Key: 0x2 Not Ready, Segment 0
Sense Code: 0x3A Qual 0x00 (medium not present) Fru 0x0
Sense flags: Blk 0 (not valid) 
cmd finished after 0.010s timeout 40s
readcd: Device not ready.
$
=================================================================

Does this above mean that the first sector is damaged?  How to proceed from 
here?

-- 
Regards,
Mick