On Thu, 2004-06-03 at 17:55, Ed wrote:
> Nick Rout wrote:
> 
> >On Tue, 2004-06-01 at 22:03, Paul Wilkins wrote:
> >  
> >
> >>Ed wrote:
> >>
> >>    
> >>
> >>>I have been trying to install Mandrake 10 official on my PIII-733 with 
> >>>320MB of ram. I have installed it once or twice successfully on this 
> >>>machine before but it doesn't work anymore. It seems halfway through 
> >>>the installation, my cd-rom drive stalls. It goes quiet and makes a 
> >>>very slight scratching noise.
> >>>      
> >>>
> >>Could the drive be having trouble reading the disc?
> >>    
> >>
> >
> >does the cd's md5sum check out?
> >
> >
> >  
> >
> i'm not exactly sure what an md5 sum is but i can tell you that it was 
> installed on another computer successfully with the same discs.

ok sorry, an md5sum is a number arrived at by applying the md5 algorithm
to a series of data. basically it is a guarantee [1] that what *you*
have is what you are *meant* to have .

on a linux box you rin, for example the command, 

[EMAIL PROTECTED] gentoo $ md5sum gensmall.iso
b2c244923a0ddf4b266fb2bf665f65ac  gensmall.iso

the number starting b2c244... is the mdksum of the file gensmall.iso.
The distributor of gensmall.iso will publish the file's original md5sum
on its web site, if you get the same number as they advertise, then you
know that the file was not corrupted when you downloaded it. 

If you have written a cd from the iso, and the cd is in /dev/cdrom, then
you can check its md5sum as follows:

cat /dev/cdrom | md5sum

[1] there are statistical possibilities of identical md5sums from two
different files. Think about 16^32 possible md5sum numbers, and the
infinite variety of possible files in the universe. However a difference
of one byte in the file will make a big difference in the md5sum.
Consider this:

[EMAIL PROTECTED] gentoo $ echo "1234"|md5sum
e7df7cd2ca07f4f1ab415d457a6e1c13  -
[EMAIL PROTECTED] gentoo $ echo "1235"|md5sum
0fa924209085a5713f79e6a30649455f  -

The difference between the string "1234" and "1235" is similar to the
osrt of difference you might get on a corrupted download, or a corrupted
cd-write, but gives a completely different md5sum.

Here endeth the lesson. It sounds like your cd is ok, so you must look
for other reasons for the failure, like hardware difficulties. SImply
speaking installing a distro from a cd really tests out the interaction
of your ide bus, the cd-rom drive, and how the whole lot copes with
cdr/cdrw. Some combinations of hardware just crap out on the very long
concerted file transfers on an install, particularly from cdr/cdrw. Try
writing the cd at 2x or 4x speed. try swapping out he cd drive for
another one. try swapping the cd-drive to another ide channel.

> 
> Ed.
> PS. it would be good if you could tell me what an md5 sum is.

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