[CentOS] CentOS5 consistent media check failures 2 - 6.

Mon Apr 23 03:00:05 UTC 2007
Maciej Zenczykowski <maze at cela.pl>

My suggestions:

verify the md5sum's / sha1sum's of the burned CD/DVD's.  (Since you 
already have the apparently correct iso downloaded to disk).  How?

like this:

dd if=/dev/dvd bs=xxx count=yyy | md5sum

(/dev/dvd is your dvd/cd whatever device, might be /dev/cdrecorder, 
/dev/cdrw, /dev/dvd, /dev/dvdrw, /dev/hda, /dev/hdb, /dev/hdc, /dev/hdd, 
etc... you should know ;-) )

Where xxx and yyy satisfy the constraint xxx * yyy = size of iso image in 
bytes.  Preferably you want xxx as large as possible.  Since iso's are 
written in 2KB sectors, you can always use 2048 for xxx, but bigger is 
better (better = faster).

If I've lost you, then just do:

dd if=/dev/dvd bs=2048 count=$[$ISOSIZE/2048] | md5sum

Where you would replace the three dots with the size of the iso image that 
should have been burned to that cd/dvd.

This will allow you to do a mediacheck by hand.  I'd venture to guess 
they'll fail... if so, then burn on good media at minimum speed (ie. like 
1x, or 2x, or something) - although I know you've tried this...  I'll just 
add my 2c - I burnt the DVDs with no problem at 4x, and the above 
mentioned verification passes.