iso md5sum ok, individual file md5sum not ok

[asynchronous13]

I downloaded 8.10 server, checked the md5sum on the .iso file and it matched. But on installation I got an error.

Checked the md5sum of the files on the burned CD:

./install/netboot/pxelinux.cfg/default: Not a directory
./install/netboot/pxelinux.cfg/default: FAILED open or read
./install/netboot/pxelinux.0: FAILED

So I tried again -- downloaded 8.10 server from a different mirror, again checked the md5sum of the .iso, and it checks out fine.

Burned the cd and double-checked the md5sum of the files, got the same error as above. Both of these files are 0 byte files on the CD.

Searching the forums turns up this error several times, but no real solution is offered.

2005
http://ubuntuforums.org/showthread.php?t=37916
http://ubuntuforums.org/showthread.php?t=19228
http://ubuntuforums.org/showthread.php?p=302532
https://lists.ubuntu.com/archives/ubuntu-users/2005-June/039378.html

2006
http://www.mail-archive.com/ubuntu-bugs@lists.ubuntu.com/msg35096.html

2007
http://www.mail-archive.com/ubuntu-bugs@lists.ubuntu.com/msg572282.html

I'm not sure how the downloaded .iso md5sum is good, but then the burned CD md5sum fails (but only for 2 files). I'm using WinXP pro sp3, burning with CDBurnerXP Pro 3, cd drive is a Sony CDRW/DVD CRX830E, burning to CD-R. Using Cygwin for md5sum. Thoughts or help would be appreciated.

[taurus]

How fast did you burn the ISO image? If you used the default speed, try burning it again with a slower speed like 4x.

[gpsmikey]

Couple of things come to mind -- I have had problems with bad media before and you may be seeing that sort of issue - try a different batch/brand of media (and burn slow). You might also try doing it with my favorite utility (free !! ) imgburn - runs very well under XP -- make sure you check the box to verify after burning - it will burn the CD then go back and read it to verify all is well. Listen for the drive to start "hunting" (speeding up/down etc) when it runs into a problem area on the disk. With the disks I use (Taiyo Yuden), a verify starts and it reads at a constant speed all the way through.

http://www.imgburn.com

mikey

[asynchronous13]

Well, this is odd.

Computer 1 - WinXP laptop
Computer 2 - to become home server
CD1 - first download and burn
CD2 - 2nd download and burn

First, CD1 failed to install Ubuntu server on Computer 2. Ubuntu Disk check revealed errors. md5sum of CD1 on Computer 1 revealed errors. md5sum of .iso on Computer 1 was ok.

Next, re-download iso (just to be sure). md5sum on 2nd iso checks out. md5sum of CD2 reveals errors, again.

I decided to try and install anyway. Ubuntu Disk check of CD2 on computer 2 passed! So I installed anyway, and CD2 works.

Both CDs have the exact same md5sum errors on my laptop, but on the other computer, CD2 passes and CD1 fails.

Odd.

[psusi]

What speed did you burn the disks at? Years ago I used to see problems with reading a cd in an older slower reader than the speed the cd was burned at. Like trying to read a cd in an older 4x reader that was burned at 8x.