lfs-book-zh_CN/chapter05/gzip-exp.xml

<sect2>
<title>Command explanations</title>

<para><userinput>cp $LFS/usr/bin/gunzip $LFS/usr/bin/gzip $LFS/bin
&amp;&amp; rm $LFS/usr/bin/gunzip $LFS/usr/bin/gzip:</userinput> The reason
we don't simply use <quote>mv</quote> to move the files to the new location
is because gunzip is a hardlink to gzip. On older distributions you can't
move a hardlink to another partition (and it's very possible that $LFS and
$LFS/usr are separate partitions). With more recent distributions this
isn't a problem. If you run mv to move hardlinks across partitions it'll
just do a regular <quote>cp</quote> and discard the hardlink. But, we
can't assume that every host distribution has a new enough kernel and
fileutils that works this way.</para>

</sect2>