I installed Ubuntu 12.04 a few weeks ago, from a download off of the website. I still have the dvd used. I was talking to my friend today about it and he mentioned something about checking the hash to make sure it was a good copy, as sometimes the file can get corrupted by a third party. My question is, can I check the hash of the dvd or even off of the versio
No, you should not be worried, and yes, it can be checked. Checking a hash is a universal procedure. While not technically correct, a hash is basically a "one-way encryption" that give a short, usually-unique code to check if the file became garbled. If it installed properly, chances are it's a good file. If you still have the ISO file around, checking the hash is quite easy. Copy it to your home folder and call it
and it will give a string(it could take some time depending on the speed of your computer). It should correspond to the strings on https://help.ubuntu.com/community/UbuntuHashes/, depending on what file you downloaded. It's most likely:
but it could be something else on that page.
You CAN generate checksums of whole DVDs even if you don't have the image anymore. Figure out the device name of your DVD drive and just run md5sum upon the device.
All Ubuntu ISOs should contain a
This checks all md5 files in a directory, shows a progress bar and finally statistics (good files, damaged files, etc).
One step further:
This will check all md5 files in a directory and subdirectories.
Note: The hash for the whole ISO at the download page is for checking the download and detect man in the middle attacks, the MD5 hashes on the ISO are for verifying the content once it's burned or transfered another way to a medium.