<div class="markdown-here-wrapper" id="markdown-here-wrapper-246443" style="font-size:1em;font-family:Helvetica,arial,freesans,clean,sans-serif;color:rgb(34,34,34);background-color:rgb(255,255,255);border:none;line-height:1.2">

<p style="margin:1em 0px">Hi all, 

</p>
<p style="margin:1em 0px">I change the machine hostname by using follow commands
</p>
<pre style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;font-size:1em;line-height:1.2em;overflow:auto;margin:1em 0px"><code class="lang-bash bash" style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:nowrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline;white-space:pre;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;border:1px solid rgb(204,204,204);padding:0.5em 0.7em;display:block;padding:0.5em;color:rgb(51,51,51);background-color:rgb(248,248,255);background-repeat:initial initial">$ hostname <a href="http://puppet-master.domain.com">puppet-master.domain.com</a>
$ sed -i <span class="string" style="color:rgb(221,17,68)">'s/HOSTNAME=.*/HOSTNAME=<a href="http://puppet-master.domain.com/">puppet-master.domain.com/</a>'</span> /etc/sysconfig/network</code></pre>
<p style="margin:1em 0px">But when checking it. I got following output
</p>
<pre style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;font-size:1em;line-height:1.2em;overflow:auto;margin:1em 0px"><code class="lang-bash bash" style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:nowrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline;white-space:pre;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;border:1px solid rgb(204,204,204);padding:0.5em 0.7em;display:block;padding:0.5em;color:rgb(51,51,51);background-color:rgb(248,248,255);background-repeat:initial initial">$ hostname
<a href="http://puppet-master.domain.com">puppet-master.domain.com</a>
$ hostname --long
puppet-master.domain.com.novalocal

$ hostname -A
localhost</code></pre>
<p style="margin:1em 0px">If I add the ip-domain mapping to the <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:nowrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline">/etc/hosts</code> file, it became right. 
</p>
<pre style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;font-size:1em;line-height:1.2em;overflow:auto;margin:1em 0px"><code class="lang-bash bash" style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:nowrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline;white-space:pre;border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;border:1px solid rgb(204,204,204);padding:0.5em 0.7em;display:block;padding:0.5em;color:rgb(51,51,51);background-color:rgb(248,248,255);background-repeat:initial initial">$ <span class="keyword" style="color:rgb(51,51,51);font-weight:bold">echo</span> <span class="string" style="color:rgb(221,17,68)">"10.0.0.10 <a href="http://puppet-master.domain.com">puppet-master.domain.com</a> puppet-master"</span> >> /etc/hosts
$ hostname
<a href="http://puppet-master.domain.com">puppet-master.domain.com</a>
$ hostname --long
<a href="http://puppet-master.domain.com">puppet-master.domain.com</a>

$ hostname -A
<a href="http://puppet-master.domain.com">puppet-master.domain.com</a></code></pre>
<p style="margin:1em 0px">I want to know why the hosts contents affect the <code style="font-size:0.85em;font-family:Consolas,Inconsolata,Courier,monospace;margin:0px 0.15em;padding:0px 0.3em;white-space:nowrap;border:1px solid rgb(234,234,234);background-color:rgb(248,248,248);border-top-left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3px;border-bottom-left-radius:3px;display:inline">hostname</code> command</p>


</div><div class="markdown-here-signature">-- <br><div><span style="font-family:arial,sans-serif;font-size:13px;border-collapse:collapse">Lei Zhang</span></div><div><span style="font-family:arial,sans-serif;font-size:13px;border-collapse:collapse"><br>

</span></div><div><font face="arial, sans-serif">Blog: <a href="http://jeffrey4l.github.com" target="_blank">http://jeffrey4l.github.com</a></font></div><div>twitter/weibo: @jeffrey4l</div><br>
</div>