Tuesday, June 27, 2006

Who was that masked man?

Installing Suse 10.1

Most of the time I like to download via bittorrent, but I didn't this time.
I always check the MD5SUMS of ISOs before burning CDs, but I didn't this time.
If the installer has a function to validate the CDs I always use it, except for this time.

So, it should come as no surprise that CDs two and five were cut from corrupted ISOs, causing the install to bomb.

So, now I have to download the ISOs for CDs two and five again. But wait, what's that in the sky? Is it a bird? Is it a plane? Is it a pheasant? Is it perhaps a large slice of cheesecake, or a gorilla in a man-suit?

But, anyway, back to the story...

When we last met our intreped installaholic had just discovered that two of the five disc images he downloaded were corrupt. Possibly due to it being an election year, or something. Watch now as he learns an important lesson - all that glitters is not glitter, although most of it probably is.

... So, faced with the daunting task... well, not exactly daunting, because I am so damn good I am practically a superhero, or a lesbian pirate... So, faced with the oh so trivial task of downloading two full discs all over again, which would put an end to my plan of finishing the Suse install tonight, I laugh a mocking laugh, a manly mocking laugh. "Ha Ha," I laugh, mockingly, for I have a plan.

I navigate to the opensuse download page, and click the link to the torrent file. Bittornado pops up and asks where I would like to save the files. Now here is the tricky bit. The clever bit. I tell it to put them in ~/downloads, which just happens to be the exact location of the five Suse Linux 10.1 ISO images I have previously downloaded.

The next thing that happens is bittornado analyzes the existing files, works out which chunks are corrupt, downloads those chunks, and repairs the corrupted ISO images. Total bytes downloaded: approximately 512K - a saving of almost 1.2G. Where I come from we call that "not too shabby", or possibly we call it "Fred", depending on whether we've taken our medication.

12 comments:

Anonymous said...

HAHAH You are a great writer. I actually did not know I could fix ISOs like that - but it still doesn't help when the only peers that are online HAVE that corrupt file. I remember a time where the file was 99.9% done but no one had that last .1% that wasn't currupt - so it was downloaded and dropped every time. I love torrenting as much as the next nerd, but sometimes it can work like a cancerous cell.

MADCAP said...

Torrents can fix bad parts too? This is interesting. But if the files are already 100%, shouldn't it just report that it's done or somethin?? This stuff is heavy man!

Ben said...

Anon:
Repairing files with bittorrent hasn't failed me yet.

Madcap:
The torrent contains an MD5SUM for each chunk of the file. BT calculates an MD5SUM for each chunk of the actual file on your drive, and compares it with its own. If they don't match, it downloads that chunk again and repairs the file.

keith said...

Too cool!

Stupid me, when I get a corrupt iso I have been deleting them and downloading them all over again. uugghh! Really sucks when you are downloading a DVD iso.

Ben said...

Yes, well it does very much depend on finding a torrent that matches the iso you've downloaded, but in the case of Linux distros that's usually pretty easy.

Lorraine said...

Crap, that was long

MADCAP said...
This comment has been removed by a blog administrator.
MADCAP said...

Hey thats why they say u dont need to check md5sum when u download an iso using torrent... I never got that part. Not that I know a lot about md5sums n' all. But makes sense now at least. Thanks...

P.S. That above comment of mine was deleted by me... lol! I was just checking what that trash does... Now I know it deletes my own comments.

Ben said...

Lorraine:
NRR

Madcap:
I am a computer thingy expert, so I know all about stuff like that. For example, did you know there's a little man who runs around inside your computer and puts ones and noughts in tiny boxes?

Lorraine said...

ahhh I love it when you get snarky with short words :)

Anonymous said...

Damn, that's good.

Anonymous said...

Finally something that makes a lot of sense, and to think that I have been wasting all of my time downloading complete iso and sometimes the complete set just because of a corrupted disk.

Bittorrent it is from now on.

Thanks for the tip.