As part of my Linux backup scheme I've recently been swapping and upgrading/replacing some USB hard disks at home. There's a Linux box at home (a Thinkpad T43p running Ubuntu if you must know) that has a 320GB disk attached and mounted as /mnt/backup and was running fairly low on space. That was after I moved about 50GB of stuff off it last night.

I want to replace it with a newly attached 750GB disk and need to move all the data over to the new disk. But since much of the data consists of remote filesystem snapshots produced using rsnapshot, which makes copious use of hard links, it's rather important that I do this correctly. If I don't, the data won't even fit on the 750GB disk!

Digging deep into my Unix past, I remember needing to do this once before. The trick was not to use any of the usual suspects: cp, tar, rsync, or mv. Instead, you use either dump (yuck) or a combination of find and cpio.

Then you just wait a long time while stuff scrolls by and you wish you were using disks in eSATA enclosures rather than in USB 2.0 enclosures.

The trouble is that cpio didn't properly preserve timestamps on directories, so I had to dig even deeper to remember pairing up dump and restore.

Next time I have to go through this, it won't take me nearly as long to devise a scheme to get it done.

Now, does anyone have alternative methods? Or do you know why cpio didn't preserve timestamps correctly?