Transfer large files/directories with no overhead over the network

ssh user@host "cd targetdir; tar cfp - *" | dd of=file.tar
This invokes tar on the remote machine and pipes the resulting tarfile over the network using ssh and is saved on the local machine. This is useful for making a one-off backup of a directory tree with zero storage overhead on the source. Variations on this include using compression on the source by using 'tar cfvp' or compression at the destination via ssh user@host "cd dir; tar cfp - *" | gzip - > file.tar.gz

6
By: bwoodacre
2009-03-18 07:43:22

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  • Finds all directories containing more than 99MB of files, and prints them in human readable format. The directories sizes do not include their subdirectories, so it is very useful for finding any single directory with a lot of large files. Show Sample Output


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    du -hS / | perl -ne '(m/\d{3,}M\s+\S/ || m/G\s+\S/) && print'
    Alioth · 2009-03-25 18:06:53 1
  • I don't like doing a massive sort on all the directory names just to get a small set of them. the above shows a sorted list of all directories over 1GB. use head as well if you want. du's "-x" flag limits this to one file system. That's mostly useful when you run it on "/" but don't want "/proc" and "/dev" and so forth. Remember though that it will also exclude "/home" or "/var" if those are separate partitions. the "-a" option is often useful too, for listing large files as well as large directories. Might be slower.


    0
    du -mx [directory] | grep -P '^\d{4}' | sort -rn
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What Others Think

the p switch to tar is not necessary in creation ("c") mode. Also, dd is not necessary, simply redirecting with "> file.tar" is enough.
cran · 482 weeks and 6 days ago
remember that * won't capture .dotfiles and .dotdirs/
linuxrawkstar · 482 weeks and 6 days ago
Why not gzip before downloading? ssh user@host 'cd dir; tar zcf - .' > file.tgz
isaacs · 481 weeks and 4 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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