Hash doesn't match for CD install

[ThunderBill]

Dell Inspiron 5150 w/ Windows XP Pro is running out of steam and has no room to grow. Not a HD problem nor Ram but OS problem. MS says I can't run W7 (and most likely W8 so my only option was try Linux. Ubuntu seemed like a simple upgrade path but, boy, was that wrong!

What is this nonsense about hash checking? I never had to do anything remotely like that with any Windows package. And then the process doesn't work as advertised. This recommended program, winMd5sum, either doesn't know how to count or the online hash list is wrong. After two tries and most of a day and a half it still can't come up with the right number. In nearly a half century of electronics and computer experience I've never had so much trouble with what should be a simple installation.

It would be great if someone could help get this process back on track and tell me what went wrong.

[vexorian]

This "non-sense" about hash checking is there to prevent you from installing a corrupted version of the ISO you download due to a network issue. If you had to download windows ISOs it would be a good idea to do it as well. Also, if you got the ISO from the official torrent, there should be no problem (torrents do hash checking automatically). It might be annoying the first time, but I guess it would be more annoying if you installed a damaged version of the disk and it destroyed your computer or something...

Anyway, since you are not specifying what ubuntu version you are trying to download. I am gonna guess that you downloaded 12.04.1 but are looking at the hash listings of 12.04 (without .1). Or maybe your network has disconnect issues and you are not being able to download the image completely. (unlikely but has happened). If you give more details (What is the md5sum you get, what is the list you are checking against, etc).


Here's a trick: When you generate a md5 sum. Try putting it in google. And check out what comes up. If the ISO is correct, chances are that the first result is going to be ubuntu.

[Peripheral Visionary]

The hash checksum is a way of ensuring that the downloaded image wasn't corrupted during the download before you burn it to a CD or DVD. If the checksums don't match, just download the iso again and check to make sure the checksums match. It's a nice little safety feature, that's all.

[audiomick]

Doing the MD5Sum is a good idea, and is in fact a really simple process normally. I have to admit, though, that I have had exactly the problem that Vexorian described, i.e. I couldn't find a checksum to match the iso I had downloaded. It was a LTS, and I came to the conclusion that the image had been updated, but the checksum had not been updated. I went ahead and installed it, and it all worked fine. Just lucky, I suppose.

[jrog]

Anyway, since you are not specifying what ubuntu version you are trying to download. I am gonna guess that you downloaded 12.04.1 but are looking at the hash listings of 12.04 (without .1).

I'm guessing this is the source of the problem. It's happened to me in the past, and, from what I recall, it was a bit more difficult to find the checksums for 12.04.1 -- I think some of the links on the Ubuntu website (can't find them now) link to 12.04 rather than 12.04.1.

Here's a trick: When you generate a md5 sum. Try putting it in google. And check out what comes up. If the ISO is correct, chances are that the first result is going to be ubuntu.

Good advice. Googling for "Ubuntu checksums" might help, too; I think that's how I've had to find 12.04.1 before.

[ThunderBill]

Dell Inspiron 5150 w/ Windows XP Pro is running out of steam and has no room to grow. Not a HD problem nor Ram but OS problem. MS says I can't run Win7 (and most likely W8 ) so my only option was try Linux. Ubuntu seemed like a simple upgrade path but, boy, was that wrong!

What is this nonsense about hash checking? I never had to do anyting remotely like that with any Windows package. And then the process doesn't work as advertised. This recommended program, winMd5sum, either doesn't know how to count or the online hash list is wrong. After two tries and most of a day and a half it still can't come up with the right number. In nearly a half century of electronics and computer experience I've never had so much trouble with what should be a simple installation.

It would be great if someone could help get this process back on track and tell me what went wrong.

[einonm]

Hi,

Some pasting of the commands you are using and output (including the hashes) would be most useful.

The hash basically checks all the bytes of a download and ensures that the downloaded image is not corrupted. If the hashes are different, chances are that the download is corrupted in some way (either during the transfer or writing to disk).
Exactly the same thing can happen for any file (including windows files), but with hash checking you get to find out about it sooner before you try and install a corrupted OS - and that's a good thing, right?

[coffeecat]

Threads merged.

@ThunderBill, please do not post duplicate threads. This dilutes community effort.

[Wim Sturkenboom]

If the hash verification fails, your download (more than likely) is corrupt. Or you're verifying the wrong version.

For reference (not specific for OP):
http://ubuntu.virginmedia.com/releases/, scroll a little down to where you see the directory tree, click your Ubuntu version, scroll again down and click the file 'MD5SUMS'

For a standard 12.04.1 (64bit) desktop, you will find (in that file) that the md5sum is 06472ddf11382c8da1f32e9487435c3d

[jrog]

What is this nonsense about hash checking? I never had to do anyting remotely like that with any Windows package. And then the process doesn't work as advertised. This recommended program, winMd5sum, either doesn't know how to count or the online hash list is wrong. After two tries and most of a day and a half it still can't come up with the right number. In nearly a half century of electronics and computer experience I've never had so much trouble with what should be a simple installation.

Even though this is a double-post and I'm mostly echoing what others have already said...

First, just because something is different does not mean that it is "nonsense." This isn't nonsense; it's a type of check that increases your security to some degree. The real "nonsense" is that this hasn't been done for other packages you've downloaded.

Second, others have tried to help you here. Have you tried their suggestions?