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copied!<p>On the difference between cp and tar to copy the directory hierarchies, a simple experiment can be conducted to show the difference:</p> <pre><code>alastair box:~/hack/cptest [1134]% mkdir src alastair box:~/hack/cptest [1135]% cd src alastair box:~/hack/cptest/src [1136]% touch foo alastair box:~/hack/cptest/src [1137]% ln -s foo foo-s alastair box:~/hack/cptest/src [1138]% ln foo foo-h alastair box:~/hack/cptest/src [1139]% ls -a total 0 -rw-r--r-- 2 alastair alastair 0 Nov 25 14:59 foo -rw-r--r-- 2 alastair alastair 0 Nov 25 14:59 foo-h lrwxrwxrwx 1 alastair alastair 3 Nov 25 14:59 foo-s -> foo alastair box:~/hack/cptest/src [1142]% mkdir ../cpdest alastair box:~/hack/cptest/src [1143]% cp -rfp * ../cpdest alastair box:~/hack/cptest/src [1144]% mkdir ../tardest alastair box:~/hack/cptest/src [1145]% tar cf - * | (cd ../tardest ; tar xf - ) alastair box:~/hack/cptest/src [1146]% cd .. alastair box:~/hack/cptest [1147]% ls -l cpdest total 0 -rw-r--r-- 1 alastair alastair 0 Nov 25 14:59 foo -rw-r--r-- 1 alastair alastair 0 Nov 25 14:59 foo-h lrwxrwxrwx 1 alastair alastair 3 Nov 25 15:00 foo-s -> foo alastair box:~/hack/cptest [1148]% ls -l tardest total 0 -rw-r--r-- 2 alastair alastair 0 Nov 25 14:59 foo -rw-r--r-- 2 alastair alastair 0 Nov 25 14:59 foo-h lrwxrwxrwx 1 alastair alastair 3 Nov 25 15:00 foo-s -> foo </code></pre> <p>The difference is in the hard-linked files. Notice how the hard-linked files are copied individually with <code>cp</code> and together with <code>tar</code>. To make the difference more obvious, have a look at the inodes for each:</p> <pre><code>alastair box:~/hack/cptest [1149]% ls -i cpdest 24690722 foo 24690723 foo-h 24690724 foo-s alastair box:~/hack/cptest [1150]% ls -i tardest 24690801 foo 24690801 foo-h 24690802 foo-s </code></pre> <p>There are probably other reasons to prefer tar, but this is one big one, at least if you have extensively hard-linked files.</p>

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