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    <p><strong>Short answer:</strong> Use <code>bsdtar</code> to create archives, and GNU <code>tar</code> to extract them on another box.</p> <p><strong>Long answer:</strong> There are some requirements for this to work.</p> <p>First, Linux must be at least kernel 3.1 (Ubuntu 12.04 or later would do), so it supports SEEK_HOLE functionality.</p> <p>Then, you need tar utility that can support this syscall. At the moment, GNU <code>tar</code> does not support it, but <code>bsdtar</code> does - install it using <code>sudo apt-get install bsdtar</code>.</p> <p>While <code>bsdtar</code> (which uses <code>libarchive</code>) is awesome, unfortunately, it is not very smart when it comes to untarring - it stupidly requires to have at least as much free space on target drive as untarred file size, without regard to holes. GNU <code>tar</code> will untar such sparse archives efficiently and will not check this condition.</p> <p>This is log from Ubuntu 12.10 (Linux kernel 3.5):</p> <pre><code>$ dd if=/dev/zero of=1tb seek=1T bs=1 count=1 1+0 records in 1+0 records out 1 byte (1 B) copied, 0.000143113 s, 7.0 kB/s $ time bsdtar cvfz sparse.tar.gz 1tb a 1tb real 0m0.362s user 0m0.336s sys 0m0.020s $ ls -l total 8 -rw-rw-r-- 1 autouser autouser 1099511627777 Nov 7 01:43 1tb -rw-rw-r-- 1 autouser autouser 257 Nov 7 01:43 sparse.tar.gz $ </code></pre> <p>Like I said above, unfortunately, untarring with <code>bsdtar</code> will not work unless you have 1TB free space. However, GNU tar works just fine to untar such <code>sparse.tar</code>:</p> <pre><code>$ rm 1tb $ time tar -xvSf sparse.tar.gz 1tb real 0m0.031s user 0m0.016s sys 0m0.016s $ ls -l total 8 -rw-rw-r-- 1 autouser autouser 1099511627777 Nov 7 01:43 1tb -rw-rw-r-- 1 autouser autouser 257 Nov 7 01:43 sparse.tar.gz </code></pre>
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    1. COAwesome! I guess the SEEK_HOLE plays the trick! I tried the `tar` and `cp` on a 3.6.5 Linux kernel and both are very fast. Thanks!
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    2. COIs the requirement of Linux kernel 3.1 or later the case even if using a later version of libarchive? It looks like there's code which makes use of FIEMAP ioctl in versions 3.x of libarchive. https://github.com/libarchive/libarchive/blob/master/libarchive/archive_read_disk_entry_from_file.c#L1011
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