How do I Know that my Download was Successful?

With the release of ANSYS 14.0, I thought it would be good to get this topic on the Focus blog. Quite often, we get tech support calls about installs that crash or hang. Most of the time it is traced back to the fact that the download was not complete or had an error that the user didn’t see at the time.  So how can you check that your download was successful before starting you install?  Easy. Check the md5sum.

When you go to download software from ANSYS, or many other locations, they post the md5sum hash table value as shown below.

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Md5sum is an algorithm used to calculate an identifier that functions as a compact digital fingerprint of a file.  Most UNIX and LINUX systems have it as a built in function. The Wikipedia article on md5sum says that Windows has it too, but I have never found it. So I went out on the internet and found one. Many actually. Here is a direct link to get MD5Sums, a useful one at PC-Tools.net, a  reputable download site.

“Md5sums” is nice in that it is fast, taking only about 30 seconds for a 4GB file, and you can use it two ways.  As with most other executables, you can use it at a command line or in a script, like this:

md5sums –u *winx64* > checksums.txt

to get a file, “checksums.txt”, with formatted output like this for all the matching files in a directory.

9febae323d5df015187c84f373db7a45 *ansys140_winx64_dvd1.iso
c90e04fd5e5bd94d1a39101bcbe18258 *ansys140_winx64_dvd2.iso

But MD5sums also allows you to drag-n-drop files onto it in the file explorer  and it starts processing those files, or a whole directory, in pop-up window. 

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Then you just compare the output to the md5sum values that ANSYS posted on the download page.  If they are not the same, then something happened during the download process.  You’ll have to download the bad file again, but at least you haven’t started the install yet.  

Happy Downloads!!!