Trying to backup the contents of a 2 TB external drive to another of equal capacity. Finder copying is extremely slow. Is there a quicker alternative?

  • cp does it file at a time, writing file system entries etc... You can clone the drive (copies sectors regardless of what's in them).. help.ubuntu.com/community/DriveImaging
    – guiverc
    Jul 16, 2018 at 2:27
  • Have you tried cp -b ? Jul 16, 2018 at 3:20
  • tar cf - . | pv | (cd /mountpoint; tar xf -) should be the quickest. BUT your question contains a trap: backups are not about being QUICK. They are about being SECURE. You really should use the answer by Sebastian regardless of speed and time. If it is a USB2 connection a USB3 connection will give you the most speed increase.
    – Rinzwind
    Jul 16, 2018 at 13:56

1 Answer 1


I would recommend using rsync for this:

rsync -avP /disk1/ /disk2

while /disk1 and /disk2 are the mount points of your two disks. The -a flag will keep file metadata intact and -vP will give you a verbose progress indicator.

Main advantage is that you can stop the process at any time and continue later simply by running the same command again.

  • But it will not be quicker ;-)
    – Rinzwind
    Jul 16, 2018 at 13:20
  • But it is more fail safe, which is preferable for backups Jul 16, 2018 at 13:21
  • I didn't measure, but I would think it's also quicker than using any GUI tool. But that's just guessing. Jul 16, 2018 at 13:23
  • Oh, I agree on all the benefits but it wont be quicker and that's his main concern :D tar is going to be the quickest tool (and will also be less secure ;) ) Oh the memories that haunt me after my boss asked me the same question. It took us 8 weeks of testing :-X
    – Rinzwind
    Jul 16, 2018 at 13:23
  • I agree tar is faster. If you get it right and error free the first time. Jul 16, 2018 at 13:26

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