Tutorials:Calculating Hash Sum

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Revision as of 01:45, 19 February 2011 by StopSpazzing (talk | contribs) (changes based on suggestions applied.)

Introduction

This guide will help to confirm you have exact copies of UBCD ISO to prevent any problems later down the road. This should be your FIRST step before continuing with any of the other Tutorials regarding the ISO. Compare with Download Page MD5/SHA1 Sum. If you would like more information regarding Checksums/Hashsums please see the Wikipedia article.


NOTE: If you can download through the torrent instead of HTTP/FTP, it can prevent you from having to check the ISO Checksum/Hashsum as it auto-checks the ISO. Thought, that being said, it still doesn't hurt to re-check.


DISCLAIMER: The only trusted source for the Torrent file is on the downloads page.

Windows

  • 2. After installation (or extraction for portable), drag ISO onto program (or desktop shortcut) and it will auto generate the MD5 Sum.

Linux

Ubuntu and similar flavors:

  • 1. First open a terminal and goto the directory you downloaded the ISO into:
cd download_directory
  • 2. Then run the following command from within the download directory.
md5sum UBCD###.iso
  • 3. md5sum should then print out a single line after calculating the hash:
CHECKSUM_HERE UBCD###.iso

# = version number

Checksum/Hashsum Doesn't Match?

Your options are:

  • 1. Re-download. Delete the ISO and download again, this time try choosing another mirror. Probably the easiest option that will work for everyone, only problem is on a slow connection could take forever (again).

  • 2. Torrent. If you can, fastest way to get the correct copy, but more complicated, is to open the torrent file in your favorite Bittorent program and start the download. Then stop the download, and copy the mismatched ISO to the download/temp location, overwriting the torrent download ISO. Followed by forcing the program to re-check the file. If everything went as planned, the program will automatically download missing pieces needed to complete the ISO.

UTorrent-Picture1.jpg
Shown is uTorrent (freeware) and right clicking on the torrent to "Force Re-Check".



Note: There are many different Bittorent programs, please see documentation for your program if you are having issues.