Cloning a volume using Apple Software Restore (the asr command in Terminal) will clone any catalog damage too. If the reason you want to make the clone is to repair damage, that's not going to help.
Good point. Also related to this, most disk imaging tools will abort image creation if an IO error is encountered. That's the more frequent problem I have with time machine backup drives. People check in their machine for slowness, and I find that time machine is getting io errors or slow blocks on the TM drive when running, so it has to be replaced. Naturally people want to keep their backup history. There have been a flood of low quality (like Western Digital Passport) external 2.5" usb drives, specifically marketed as time machine backups. Those have a very high failure rate due to io errors. It's possible they're just getting handled a little more, bumped on the tables etc, and that's leading to the high failures. I think it's a combination of the two.
And related to
that, I was shown a
very clever idea recently. For those with a little 2.5" form factor usb or fw time machine drive and an imac, having one of those tethered to your imac (often with a 6" cable) begs for it to get bumped and knocked by keyboards, mice, etc. Apply several strips of velcro to the bottom of the case, the soft (loop) type. Then apply the hook type to the foot of the imac, between the hinge and the hole. Attach your drive. Keeps cables off the table and totally out of sight, and protects the drive. It's not going anywhere anyway.
