I’m trying to reinstall Ubuntu 24.04.2. I’m having problems. I wan to verify the downloaded .iso file. I can download the .iso file, and the SHA256SUM.gpg file, but everything I’ve tried fails to download the SHA256SUMS file. If I click on the name in the directory it prints three lines to a new page. If I right click and try “save link as …” I get something with a weird color and unreadable name in my Downloads file. The pages that teach how to verify downloads just say to “get the SHA256SUM and SHA245SUM.gpg files.” One suggestion was to try a mirror of the source, but apparently there are no mirrors. What can I do?
What happens when you try running the following command in Terminal? -
wget 'https://releases.ubuntu.com/noble/SHA256SUMS'
This is supposed to download the SHA256SUMS file to the current working directory.
I think those lines from opening the sha256sum with your browser all you need. You don’t need to download the file. Also, I never use with the gpg file. (If you really want a copy of those lines, just copy and paste Them to the text editor.)
cd to the download directory where the iso is, and run in terminal:
sha256sum ubuntu-24.04.2-desktop-amd64.iso
Match the output of this command with one of the three lines.
Those three lines - each made up of a checksum in hexadecimal followed by a space, a star, and a file name - are the contents of the SHA256SUMS file. It’s a simple text file. You could just right click in the page and choose ‘save page as’ and save it into the same directory as the iso. Then you can check that the iso has the right checksum by doing ‘sha256sum -c filename’ because sha256sum in check-mode reads the file given as an argument, calculates the sum for the file(s) listed in it and compares the listed checksums to the calculated ones.
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@Dennis N: That solves my problem, thanks, but I’d hoped for a program to do the comparison. It would be nice to verify with gpg, too, but I guess as long as the checksum is the same the program is good.
@hee-gehrke: I tried the “save page as” trick, and it did the same as the “save link as” trick. I did not get a text file, I got a .part file which was greyed out.
It would be nice to find out why every article I find on the internet says to save the file and gives a command line to verify the download.
Sounds like an Internet connection or browser issue. Downloading a file that small could be instantaneous.
Those are the appropriate instructions. What would you expect instead?
@wxl: Well, I would expect something like Dennis_N gave. To me, “download the file” means clicking on a link and getting a file downloaded to my Downloads directory. The SHA256SUM file doesn’t do that. Alternatively, I should be able to right click on the link and then select “save link as” and get a file in my Downloads directory, or right click on the browser screen showing the output, selecting “save page as” and getting a file in my Downloads directory. None of those things happen, so I am frustrated.
As it happens, I followed Dennis_N’s advice. Unfortunately, the checksums matched, so why is it not installing Ubuntu as installer programs have done so many times before?
Both work fine for me, thus the reason why the instructions suggest it.
Sounds like you have a separate issue from this topic. I’d suggest you mark this solved and create a new topic with a clear description.