I typically check the md5sum when I download a .ISO, but I'm about to do an upgrade (Mandrake 9.0 to 10.1) and I want to verify the burns are actually good.
A quick check on google finds this thread:
http://lists.debian.org/debian-user/.../msg00777.html
I've seen the method before, so I tried it, and it errors out after read most of the cd.
The md5 doesn't match, possibly for the reasons given in the thread.
I then used readcd, which gives the following on two different disks (errors are similar for both cd's):
Code:
[caysho@Petrata caysho]$ readcd dev=0,2,0 -f disk1
Capacity: 354053 Blocks = 708106 kBytes = 691 MBytes = 725 prMB
Sectorsize: 2048 Bytes
Copy from SCSI (0,2,0) disk to file 'disk1'
end: 354053
readcd: Input/output error. read_g1: scsi sendcmd: no error
CDB: 28 00 00 05 67 00 00 00 05 00
status: 0x2 (CHECK CONDITION)
Sense Bytes: F0 00 05 00 05 67 03 12 00 00 00 00 C6 02 00 00
Sense Key: 0x5 Illegal Request, Segment 0
Sense Code: 0xC6 Qual 0x02 (vendor unique sense code 0xC6) [No matching qualifier] Fru 0x0
Sense flags: Blk 354051 (valid)
cmd finished after 4.173s timeout 40s
readcd: Input/output error. Cannot read source disk
readcd: Retrying from sector 354048.
....~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~+~~~-~~~
readcd: Input/output error. Error on sector 354051 not corrected. Total of 1 errors.
Time total: 425.342sec
Read 708096.00 kB at 1664.8 kB/sec.
One disk is Mandrake 10.1 Official Disk 1, the other is a collection of mp3's.
This got me suspicious - the drive reading the disks in both cases is the burner that created them.
I checked a pressed CD (Mandrake 9.0) with readcd, and it was fine.
The CDR media is TDK. I haven't done this with other media before. I'm nearly finished the TDK spindle, and I've got some Sony to use next.
Am I missing something here ?
Or am I just unlucky ?
Should I just go through the md5sums of each file ? I don't know where Mandrake keeps these, if they are available.
The disks appear to work. I once did a brief install of Mandrake 10.1 on a different machine, and it had a problem finding a file, then it was ok on the second try. I'm tempted to download it again to further verify.
The cd with the mp3's work fine in my DVD player (a Sony).
