ISO Verification

Ensure correct ISO downloads

This page provides instructions for verifying the integrity of ISO files on all popular operating systems. We highly recommended you verify the Kubuntu Focus Suite ISO file immediately after download. This helps ensure you will not encounter corruption or stability issues during installation.

Verify a Kubuntu Focus Suite ISO with Dolphin.

Verify a Kubuntu Focus Suite ISO with Dolphin.

Please read the disclaimer before proceeding. We review and update guided solutions regularly. If you have suggestions or requests, please write support@kfocus.org.

Verifying KFocus Suite ISOs

This guide explains how to verify a Kubuntu Focus Suite ISO using a Kubuntu Focus system.

Verifying other ISOs

The following instructions are useful for verifying ISO files on any major OS.

Linux (with verification file)

Many ISOs have a verification hash file provided alongside them. When this is the case, most Linux systems can verify that the ISO is intact with one command, using the sha256sum tool. To do this:

  • Download the ISO file and its accompanying verification hash file. This file is usually named SHA256SUMS or iso-file.sha256.
  • Open a terminal emulator.
  • Using the cd command, navigate to the folder where the ISO and verification hash file are located. This will usually be ~/Downloads.
  • Run sha256sum -c verification-file.sha256 |& grep OK, replacing the name verification-file.sha256 as needed.
  • If you see a line of output similar to iso-file.iso: OK, your ISO download is good.
  • If you do not see any output whatsoever, or if all output refers to files other than the ISO file you downloaded, your ISO download is bad and should be deleted. If this is the case, download the ISO again.
Linux (without verification file)

Sometimes the verification hash for an ISO file is provided as a string, rather than as a separate file. When this is the case, you can verify the ISO file using the following procedure:

  • Download the ISO file.
  • Open a terminal emulator.
  • Using the cd command, navigate to the folder where the ISO is located. Often this will be ~/Downloads.
  • Run if [ 'VERIFICATION-HASH-HERE' = "$(sha256sum iso-file.iso | cut -d' ' -f1)" ]; then echo 'Good'; else echo 'Bad'; fi, replacing iso-file.iso and VERIFICATION-HASH-HERE as needed.
  • If you see a line of output that says Good, your ISO download is good.
  • If you see a line of output that says Bad, your ISO download is bad. It should be deleted and downloaded again.
Windows

Most versions of Windows provide the certutil utility, which can check ISO file verification hashes. To do this:

  • Download the ISO file.
  • Open Explorer (the file manager application in Windows).
  • Navigate to the folder where you downloaded your ISO. Usually this will be Downloads.
  • Press [ALT][D] on your keyboard. This will highlight the address bar at the top of the window.
  • Type cmd and press Enter. A command prompt window will open. Any commands run from here will run in the current folder.
  • Inside the command prompt window, run certutil -hashFile "iso-name.iso" SHA256, replacing iso-name.iso as needed. The command will process for a while, then output a sequence of numbers and letters.
  • Look at the hash provided alongside the ISO file (either by opening the verification hash file in your browser or text editor, or by viewing the page that displays this hash). Carefully compare it to the sequence of numbers and letters output by certutil.
  • If the file hashes match, your ISO download is good.
  • If the file hashes do not match, your ISO download is bad. It should be deleted and downloaded again.
macOS

macOS provides the shasum utility, which can check ISO file verification hashes. To do this:

  • Download the ISO file.
  • Open Terminal (the default terminal emulator in macOS).
  • Open Finder (the default file manager in macOS), and navigate to the folder where your download is located. Usually this will be Downloads.
  • In Terminal, type shasum -a 256 (including a space at the end), then drag and drop the ISO file from the Finder window into the Terminal window. The full path to the ISO file will automatically appear in Terminal.
  • Press Enter. The command will process for a while, then output a sequence of numbers and letters.
  • Look at the hash provided alongside the ISO file (either by opening the verification hash file in your browser or text editor, or by viewing the page that displays this hash). Carefully compare it to the sequence of numbers and letters output by certutil.
  • If the file hashes match, your ISO download is good.
  • If the file hashes do not match, your ISO download is bad. It should be deleted and downloaded again.

Troubleshooting

Content will be added as needed.

Revisions

This is a partial revision history. See the git repository for all entries.

Disclaimer

We try hard to provide a useful solution validated by professionals. However, we cannot anticipate every situation, and therefore cannot guarantee this procedure will work for your needs. Always backup your data and test the solution to determine the correct procedure for you.

THIS SOLUTION IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOLUTION, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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