I have downloaded the full Mageia 8 iso by BitTorrent. Neither Etcher
nor isodumper is able to write it to a USB stick successfully. I
checked the download and tried to use a .torrent file from Distrowatch.
Both said that the download had no problems. The report from Isodumper
was a bit more informative. It said that the checksum in the ISO was
defective and unreadable. In these circumstances, the BitTorrent
protocol should ensure that the download is O.K.

On Sat, 15 Jan 2022 23:24:06 +1100, Doug Laidlaw wrote:
> I have downloaded the full Mageia 8 iso by BitTorrent. Neither Etcher
> nor isodumper is able to write it to a USB stick successfully. I
> checked the download and tried to use a .torrent file from Distrowatch.
> Both said that the download had no problems. The report from Isodumper
> was a bit more informative. It said that the checksum in the ISO was
> defective and unreadable. In these circumstances, the BitTorrent
> protocol should ensure that the download is O.K.

I always do a checksum on the download and burn.
Saves me from creating coasters and wasting time on a bad
burn/xfer to cd or usb.

On Sat, 15 Jan 2022 07:24:06 -0500, Doug Laidlaw <laidlaws@hotkey.net.au> wrote:

> I have downloaded the full Mageia 8 iso by BitTorrent. Neither Etcher
> nor isodumper is able to write it to a USB stick successfully. I
> checked the download and tried to use a .torrent file from Distrowatch.
> Both said that the download had no problems. The report from Isodumper
> was a bit more informative. It said that the checksum in the ISO was
> defective and unreadable. In these circumstances, the BitTorrent
> protocol should ensure that the download is O.K.

Did you download the sha3 signature to the same directory as the iso image?

You can check the on disk copy with ...

# cd /downloadlocation
(for me, that's /s3/m8/Mageia-8-x86_64/ )
[root@x3 /s3/m8/Mageia-8-x86_64]# cat Mageia-8-x86_64.iso.sha3
F3DADD10FCB64BCBAC55C91B9270521520D70195BDF27CEB414E0F4960863D8C3C0EC4ECDF5AFF87868FA8133BE1A58EFB58239DDC845F5A598DD0441EF685F3 Mageia-8-x86_64.iso
[root@x3 /s3/m8/Mageia-8-x86_64]# sha3-512sum -c Mageia-8-x86_64.iso.sha3
Mageia-8-x86_64.iso: OK

Using isodumper, it will check the sha3 sum of the copy from the usb stick after
copying it, not the copy on disk. If the on disk copy is ok and the on usb stick
copy is not, then the copy failed, likely due to a bad usb stick.

If you don't have a copy of the sha3 sum file in the same directory as the iso
file, isodumper will report "The computed and stored sums don't match", since
there is no stored sha3 sum file.

I'd prefer it that it reported that the sha3 sum file was not found, though it's
not technically an error to say the sums don't match, and changing it would
involve replacing the currently used python library function with a new function
written to be written by Mageia.

I've also opened https://bugs.mageia.org/show_bug.cgi?id=29895 as the key server
hard coded in isodumper is no longer available, and the current gpg release key
has expired.

Regards, Dave Hodgins

On 16/1/22 00:04, Bit Twister wrote:
> I always do a checksum on the download and burn.
> Saves me from creating coasters and wasting time on a bad
> burn/xfer to cd or usb.
>
A fair comment, but the checksum you need is that of the CD you burned.
In my experience, that checksum never matches the one from the
download. k3b derives its own checksum before the burn. and the two
iso-dumpers would have done the same. Apparently, after the burn, the
checksum could not be read to compare. The burn might still be good.

On 16/1/22 09:05, David W. Hodgins wrote:
> Using isodumper, it will check the sha3 sum of the copy from the usb
> stick after
> copying it, not the copy on disk. If the on disk copy is ok and the on
> usb stick
> copy is not, then the copy failed, likely due to a bad usb stick.
>
What I downloaded was set by the .torrent file. It included checksums
for MD5, sha3 and sha512, with gpg files for them all, including the iso
itself.

I burned the iso to 2 different USB sticks, the USB2 one I used
originally and a fairly new Lexar USB3 one. Both burns failed.

On Mon, 17 Jan 2022 01:07:58 +1100, Doug Laidlaw wrote:
> On 16/1/22 00:04, Bit Twister wrote:
>> I always do a checksum on the download and burn.
>> Saves me from creating coasters and wasting time on a bad
>> burn/xfer to cd or usb.
>>
> A fair comment, but the checksum you need is that of the CD you burned.
> In my experience, that checksum never matches the one from the
> download. k3b derives its own checksum before the burn. and the two
> iso-dumpers would have done the same. Apparently, after the burn, the
> checksum could not be read to compare. The burn might still be good.

I use cdrecord for burning and readcd to read cd and iso for md5sum.
Code snippet follows:

echo "$_exe
#***************************************
#* Getting $_drive md5sum
#***************************************
"

_iso_bytes=$(stat $_iso_fn -c %s)
_sectors=$(( $_iso_bytes / 2048 ))

set $(readcd sectors=0-$_sectors dev=$_drive f=- | md5sum)
_cd_sum=$1

echo "$_exe
#***************************************
#* Getting $_drive md5sum
#***************************************
"

_iso_bytes=$(stat $_iso_fn -c %s)
_sectors=$(( $_iso_bytes / 2048 ))

set $(readcd sectors=0-$_sectors dev=$_drive f=- | md5sum)
_cd_sum=$1

echo "$_exe
#***************************************
#* Computing $_iso_fn md5sum
#***************************************
"
set $(md5sum $_iso_fn)
_iso_sum=$1

if [ "$_cd_sum" != "$_iso_sum" ] ; then
_fatal_msg=("md5sum mismatch"
" "
"dvd: $_cd_sum"
"iso: $_iso_sum")
fatal 1
fi

On 2022-01-16, Doug Laidlaw <laidlaws@hotkey.net.au> wrote:
> On 16/1/22 00:04, Bit Twister wrote:
>> I always do a checksum on the download and burn.
>> Saves me from creating coasters and wasting time on a bad
>> burn/xfer to cd or usb.
>>
> A fair comment, but the checksum you need is that of the CD you burned.
> In my experience, that checksum never matches the one from the
> download. k3b derives its own checksum before the burn. and the two
> iso-dumpers would have done the same. Apparently, after the burn, the
> checksum could not be read to compare. The burn might still be good.

Of course it is not the same. If you read /dev/sdb say (assuming that is
your cdrom/usbstick) it will keep reading until it comes to the end of the disk.
That will be beyond the end the file you just wrote to there with say
dd. Thus the two files are of different lenths and have differnt
contents, and the checksum will be different. You have to tell the
checksum program to only read as many bytes as you wrote.

On 2022-01-16, Doug Laidlaw <laidlaws@hotkey.net.au> wrote:
> On 16/1/22 09:05, David W. Hodgins wrote:
>> Using isodumper, it will check the sha3 sum of the copy from the usb
>> stick after
>> copying it, not the copy on disk. If the on disk copy is ok and the on
>> usb stick
>> copy is not, then the copy failed, likely due to a bad usb stick.
> >
> What I downloaded was set by the .torrent file. It included checksums
> for MD5, sha3 and sha512, with gpg files for them all, including the iso
> itself.
>
> I burned the iso to 2 different USB sticks, the USB2 one I used
> originally and a fairly new Lexar USB3 one. Both burns failed.

What do you mean "failed"? How did they fail? How do you know they
failed. Be exact in your description.

On 17/1/22 01:17, Doug Laidlaw wrote:

>
> I burned the iso to 2 different USB sticks, the USB2 one I used
> originally and a fairly new Lexar USB3 one.  Both burns failed.

I have always downloaded from the repo.
Used to burn to CD which is a long clumsy perilous process.
So I now install to USB stick with isodunmper and it has worked fine.
I have some distrust for torrents - just my paranoia

--
faeychild
Running plasmashell 5.20.4 on 5.15.11-desktop-3.mga8 kernel.
Mageia release 8 (Official) for x86_64 installed via Mageia-8-x86_64-DVD.iso