Hi John, "Wow" thanks for a comprehensive explanation and detailed instructions to do md5sum. This is very much appreciated. Johan *******************
----- Original Message ----- From: "John Richard Smith" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Monday, November 24, 2003 11:45 AM Subject: Re: [newbie] file xxxx.md5sum > Johan wrote: > > >Hi, > >Now if you have a file named xx.md5sum and a xx.iso - is there a way that > >you can check if the download is true. > >Please some pointers how to do this. > >Thanks > >Johan > > > > > The iso's have md5sums published for them, > so, > 40c8812dce7b9f8fb0a3b364af62b974 > is the md5sum of Mandrake92-cd1-inst.i586.iso > > When you have finished your download, > cd directory Mandrake92-cd1-inst.i586.iso file, > and run, > md5sum Mandrake92-cd1-inst.i586.iso and > if your iso is all there it will return, after a fairish wait, > 40c8812dce7b9f8fb0a3b364af62b974 > > Once the iso is writen to a CD as a disc(not as an iso) > it is possible to find the md5sum of the disc which will > not be the same as the iso(after all it's not an iso now,merely > the contents) but unfortuneatly they don't publish any > md5sum of the CD which would be quick and simple > so it's not going to be possible to check the sum against > any known md5sum for the CD. > > However IF you still have the original iso image file it > can be used to check the new CD , > There are several ways. > > test1 burnt cd > ============= > > ls -ls <iso-file-name>.iso to find the filesize, in bytes, of > the ISO > image > > Divide that by 2048 to find the number of sectors:(xxxxxx) > > Put the CD into a drive but don't mount it. > > dd if=/dev/(x) bs=2048 count=(xxxxxx) | md5sum - > where (x) is your device(eg. hdc, or scd0), > where (xxxxxx) is the number of sectors > > They should agree. > > The principle is the same whether checking a CD or a file created > from an iso situated on the HD. Just substitute the /dev/(x) with > path to iso imagefile, not that , so far, I've had occassion to check > this with practicable examples, but I cannot see why it should not > work. > > Problems arrise where you no longer retain the the original downloaded > iso image file.Then there is nothing to work with but the original > published md5sum for the iso image file. > > In theory one ought to be able to backtrack to the original iso image > file you downloaded by creating a new iso image file from your CD > or package file, this can be done, > > test3 burnt cd > ============== > make an ISO of the CD, > cd (destination directory) > mkisofs -r -J -v -o temp.iso /mnt/cdrom/* (full scan) > mkisofs -v -o temp.iso /mnt/cdrom/* ( troublesome file endings) > > ls > <name-of-iso>.iso > md5sum <name-of-iso>.iso > 6c7df6cc49a7abff39558a06a4e571eb <nameofiso>.iso > > In theory this should be the same as the published > iso md5sum, but it depends what criteria the packager used > to create the iso image file , the flags (-r, -J - for instance) make > a difference to the resuling md5sum, I guess it's a question of > what depth of read the mkisofs does ? > > > If you find a way, let me know , because I've deleted an iso image > file of the MD9.2 CD1 , but would like to check the burnt to CD > contents against the original md5sum for the iso.So far my > attemps have come to naught. All would be so much > simpler if the packagers merely published the iso and the CD > md5sums. > > John > > -- > John Richard Smith > [EMAIL PROTECTED] > > > > > ---------------------------------------------------------------------------- ---- > Want to buy your Pack or Services from MandrakeSoft? > Go to http://www.mandrakestore.com >
Want to buy your Pack or Services from MandrakeSoft? Go to http://www.mandrakestore.com
