sha256sum mismatch in TNG50-2

Mohammad Rad
  • 18 Jun '23

Hi all,

For the TNG50-2 snapshot_99, I have downloaded http://www.tng-project.org/api/TNG50-2/files/snapshot-99.0.hdf5 chunk file. The sha256sum for my downloaded file is:
20414ee2ba0287a053006ecffa8829df39284f821257d82dc532aab8d9cd1d2b

But in the checksum.txt it is:
854f06b2b5b6743b68f45bf395a636726e13aaede60f64ce528152f7dae94ecb snap_099.0.hdf5

To be sure I repeated downloading the file in google colab, but I got the same result. So, is the checksum.txt correct? Or are the files in the TNG server are healthy?
Thanks

Dylan Nelson
  • 18 Jun '23

I confirm that the correct checksum is

20414ee2ba0287a053006ecffa8829df39284f821257d82dc532aab8d9cd1d2b  snap_099.0.hdf5

unfortunately the provided checksum.txt files are a bit of a relic - I never found that people used them, or that they were that useful. It seems that in this case they are "old" (i.e. were computed prior to the final versions of these files).

Mohammad Rad
  • 18 Jun '23

Hi Dylan,

I would be grateful if the correct ones are provided, otherwise there is no way to find the corrupted files (as was the case for me, when I used the batch download).

Thanks

Dylan Nelson
  • 20 Jun '23

Hi Mohammad,

Have you actually found a corrupt download? Most all data transfer will, these days, be automatically verifying the integrity of the transfer at a lower level. If the file passes h5check, then it will be valid.

Mohammad Rad
  • 20 Jun '23

Unfortunately, because of heavy filtering (I guess) of internet in Iran, we have problem even to open the TNG webpage (and many other pages). In my first attempt to automatically download the chunk files, some are corrupted (their total size is different with what that should be). I were not aware of h5ceck, but I can check it.

I think, having a wrong checksum file may cause the same problem for other people.
Thanks

  • Page 1 of 1