I/O Errors
 

Since updating to the latest SD I suddenly have problems with the copy freezing on an I/O error. Here's the last few lines from the log file:

/Users
| 04:56:43 PM | Info | WARNING: Caught I/O exception(5): Input/output error
| 04:56:43 PM | Info | WARNING: Source: /Users/billsveinson/Music/iTunes/iTunes Music/Podcasts/Adobe Photoshop Killer Tips/Quickly Jumping to Different Layers.mp4, lstat(): 0
| 04:56:43 PM | Info | WARNING: Target: /Volumes/FW Boot/Users/billsveinson/Music/iTunes/iTunes Music/Podcasts/Adobe Photoshop Killer Tips/Quickly Jumping to Different Layers.mp4, lstat(): 0
| 04:56:43 PM | Info | Attempting to copy file using copyfile().

This has happened with both of my 80 GB external FW drives, one is a wall-powered standard-sized drive, and the other one is a bus-powered unit with a laptop drive. Both worked flawlessly with SD before. The failure is always as above, with the choking point always being an iTunes file. I managed to get the larger drive to complete a backup by deleting the offending file, but the small drive still chokes each time. An even bigger problem is the way that SD refuses to quit gracefully - I have to simply unplug the FireWire cable, which of course outrages the Finder and causes who-knows-what kind of corruption. Where to go from here?

I'm certain the "new version" is a red herring, Bill -- the problem here is a hardware issue. If the system's locking up and requiring FireWire to be unplugged, it's likely that a bad sector is causing the FireWire bus to lock (which hangs the I/O subsystem).

Try using Disk Utility to erase and zero the drive. Then, give it another try and see if that works.

Looks like you nailed it - I zeroed the drive and tried the clone again - worked fine this time. Many thanks! :)

Would you care to elaborate on how this could happen and why the drive passed a check with every utility I have with flying colours? (DiskWarrior, TechTool Pro, Apple Disk First Aid) How far can I trust this drive for backups now? :confused:

Destination drives, just like source drives, can go bad. And Disk Utility/Warrior/etc don't test the drive surface. They check the drive structure, but don't try to read/write files.

In this case, the data area went bad... and zeroing found and re-mapped that.

Can you trust the drive? All drives have bad areas. But, usually, the drive re-maps them "automatically". In this case, it might not have had any more spares, so the drive couldn't remap transparently.

Zeroing will typically test everything and so it's good... for now. But if you end up with another problem, I'd replace the drive.