URGENT PROBLEM: I tried to verify an external drive and it has corrupted it.

Hi,
I repaired an external hard drive in disk utility by accident and now the drive has been corrupted. I can mount the drive but it tells me that the drive is not writable any more and that I should back up the material. Problem is when I start to copy my files onto another drive it tells me it will take approx 400 hrs per 100 gigs. I have to back up approx 1tb so this rate is completely ridiculous. by my reckoning that is about 6 months.

The data on the drive is very important and I am under time constraints so any help would be greatly appreciated.

Mac Pro
Model Identifier: MacPro2,1
Processor Name: Quad-Core Intel Xeon
Processor Speed: 3 GHz
Number Of Processors: 2
Total Number Of Cores: 8
L2 Cache (per processor): 8 MB
Memory: 16 GB
Bus Speed: 1.33 GHz

Welcome to Mac-Forums

Do you happen to know what things got repaired? Can you copy files out in smaller chunks or at least save the most important stuff first?

Thanks for getting back to me Ashwin,

I don't know what got repaired. The intention wasn't to repair the disk in the first place but all the files seem to read ok. I can copy files out individually and in order of priority but the files are big HD video files so there is no getting around the volume.

Was the HD formatted for OSX or something else? I'd imagine OSX if the repair even managed to get anywhere..and usually the repair process is not destructive, but just to be clear. Did you just repair permissions or something beyond that?

If you did have some corrupted components on the HD before the repair and those got deleted, it should only affect a few files not the entire HD..

Yes it was formatted for Mac OSx. I canceled the repair once I started it and now when I start up the computer a warning comes up saying that the drives could not be repaired and telling me to back up everything up.

Ahh, so you started and canceled. That might have broken something partially..though the fact that it's saying the drives could not be repaired on boot doesn't bode well to repeating the repair process again..

You might have to go through the painful process of copying whatever files will get copied and then when you hit a wall with no more files (based on size) copying, you might want to try to do another repair and see if it somehow manages to do something to fix it..

You ran the repair with a OS X disc or recovery partition?

That doesn't sound great. I ran the repair solely through disk utility. I didn't run it with the disk or with a recovery partition.
Is there any other software that could help me like Disk Warrior?