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Is it possible to run cp again after it was aborted and make it start where it ended last time (not overwrite data that's already copied, only copy what's still left)?

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4 Answers 4

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It's cases like this that have taught me to use rsync from the start. However in your case, you can use rsync now. It will only copy new data across, including if cp stopped half way through a big file.

You can use it just like cp, like this:

rsync --append /where/your/copying/from /where/you/want/to/copy
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    Or --append-verify to compare checksums at the end just to be sure.
    – Zaz
    Commented Jun 27, 2018 at 23:57
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In case the aborted cp was a recursive copy, you might want to resume with rsync including the option --recursive.

Example

Aborted copy command:

cp -r source-directory destination-directory

Let us assume that destination-directory already existed, so that this copy command created a directory named source-directory within destination-directory. This can be resumed via:

rsync --recursive --append source-directory destination-directory

Note that trailing slashes have a precise meaning in rsync path options.

In this case, the copy command could have gotten the argument source-directory or source-directory/, it does not make a difference. In the rsync command, however, it must be source-directory without trailing slash.

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8

Use the -u switch, and see the cp man page.

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  • but source files didn't changed or anything
    – Phil
    Commented Aug 22, 2009 at 0:29
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    the -u is for 'update' only... ie: it wont overwrite the existing files in the destination if they are same or newer...
    – ericslaw
    Commented Aug 22, 2009 at 4:27
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    If you use -u, then it will copy the same big file again. -u only helps if you're trying to resume a large recursive copy.
    – Amandasaurus
    Commented Jan 14, 2010 at 17:05
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    This answer was helpful for me because in my case it was many small-ish files and no problem to just delete the incomplete files before running my initial cp -a as cp -au again.
    – msa
    Commented May 13, 2021 at 11:58
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    Should I be worried about unfinished files from the previous cp? Or the -u will take care of that?
    – Qin Heyang
    Commented Nov 1, 2021 at 18:35
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rsync is a great tool also: man page at -> http://www.manpagez.com/man/1/rsync/

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