I get an error about failed MD5 checksum or corrupt package when installing

Created by Jeff Lane on
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More often than not, issues installing from a downloaded iso are due to one of three things:

1: Your download was corrupted or incomplete. It's entirely possible to download a full ISO and still have a few corrupted bits in the middle somewhere. For that reason, any OFFICIAL Ubuntu Download site should also provide links to the MD5sums of the full ISO image.

For example, see here:

http://releases.ubuntu.com/quantal/

The first files you see contain the md5sums, sha1sums, or sha256sums for each Ubunt 12.10 ISO. to use these, do the following (for md5 but should work for sha1 or sha256 tools as well):

Make a directory in your homedir
download the ISO into that directory
download the correct sums file, in this example http://releases.ubuntu.com/quantal/MD5SUMS
now use md5sum like so:
# md5sum -c MD5SUMS (make sure you have the MD5SUMS file and ISO image int he same directory)

This will verify that the ISO is not corrupted.

Additionally, you could do this manually:

md5sum /path/to/ISO_image
which will give you the md5sum on your terminal. Then just compare that number to the one in the MD5SUMS file for the ISO you're using.

2: The next problem is usually bad CD/DVD media. Also, keep in mind that as of 12.10, our ISO image is no longer small enough to fit on a single CD disk, so you'll need to use DVD media from 12.10 going forwards. I've found that this is usually the biggest culprit. Especially when using very inexpensive bulk media. I've found that sticking to name brands like Sony or Verbatim tends to work better than when using generic blank media. I've personally seen 100CD spindles where nearly 40% of the disks were unusable due to poor quality.

So the next step is to burn a new disk, and be sure to verify the burn even though that takes some time.

3: Bad USB drive (this only applies if you're putting the ISO onto a thumbdriver/USB Key)

Usually this isn't an issue, but flash media can go bad, and it's possible to have data written to bad sectors on a flash drive. Try a different USB key and see if that helps.

Finally, if the above don't help you with that ISO, ask here:

ubuntuforums.org

or here:

askubuntu.com

and file a bug with this command:

#ubuntu-bug

and be sure to read this on filing bugs properly:

https://help.ubuntu.com/community/ReportingBugs