I am trying to backup a hard drive partition with dd, but having very odd results. It stops with an Input/Output error, but not always on the same point. (Sometimes 300-some MB, sometimes after 1 or 2 GB). I know there's the sync and noerror options to keep reading after an error and just write 0's to the file, but that solution wouldn't be good for me since it seems that certain things are only unreadable sometimes. Is there any way to simply make dd retry a block if it fails? Alternatively, is there any other good util for making an image of total drive or drive partition (ideally such that I can mount the image as a loop device just like with a dd image)?

For more info on the weird drive: I am able to e2fsck the partition just fine. I haven't actually had any problems with it before. I just can't seem to back it up.

"I am trying to backup a hard drive partition with dd, but having very odd results."

Backing up and restoring with dd is a very error prone backup method. I highly recommend that you switch to a backup and restore method based on tar.

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Steve Stites

Unfortunately, backing up with dd is the only way I know of to get an image that's mountable as a block device and also has bootsector info and such.

The two drives have to be physically identical or you'll get some weird sync errors. You didn't
say if they were the same or not so I'm not sure if that'll help or not.

Zack

Oh, I should have mentioned that I am backing up to an image file and not to another drive. My intent was to mount it as a loop device and make changes if I needed to and/or then restore it later to the same drive if the development expiriment I was running on it happened to fail. (I suppose in this case since there were read errors on the drive that I would prob. restore it to a same sized partition later, but I still need to get it backed up to the image file first).