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	<title>Jeremy Visser &#187; Linux</title>
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	<link>https://jeremy.visser.name</link>
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		<item>
		<title>Got an Android</title>
		<link>https://jeremy.visser.name/2010/08/13/got-an-android/</link>
		<comments>https://jeremy.visser.name/2010/08/13/got-an-android/#comments</comments>
		<pubDate>Fri, 13 Aug 2010 13:28:52 +0000</pubDate>
		<dc:creator>Jeremy</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[Android]]></category>
		<category><![CDATA[hardware]]></category>
		<category><![CDATA[Linux]]></category>

		<guid isPermaLink="false">https://jeremy.visser.name/?p=1538</guid>
		<description><![CDATA[This week, I got an Android phone. A Motorola Milestone, to be precise. I&#8217;ve been looking at smartphones for a while, although not quite seriously up until now. In fact, I&#8217;m quite surprised with myself that I actually took the plunge and bought something. Actually, the main push for me to get an Android phone [...]]]></description>
			<content:encoded><![CDATA[<p>This week, I got an <a href="http://en.wikipedia.org/wiki/Android_(operating_system)">Android</a> phone. A <a href="http://www.motorola.com/consumers/AU-EN/Motorola-MILESTONE-AU-EN.do">Motorola Milestone</a>, to be precise.</p>
<p>I&#8217;ve been looking at smartphones for a while, although not quite seriously up until now. In fact, I&#8217;m quite surprised with myself that I actually took the plunge and bought something.</p>
<p>Actually, the main push for me to get an Android phone was <a href="http://marty.sunriseroad.net/">Dad</a>, who wants me to get into app development. I initially held back because I like the concept and hackability of the <a href="http://maemo.nokia.com/n900/">Nokia N900</a> and the Maemo OS. Maemo uses a normal X11+GTK/Qt kind of stack, and is generally hacker friendly.</p>
<p>However, I don&#8217;t just want to hack for myself; I want to be able to release stuff, and if I do, I want people to be able to use it. Not only that, but with the merger of Maemo and Moblin becoming <a href="http://meego.com/">MeeGo</a>, and the fact that MeeGo won&#8217;t be officially supported on the N900 creates furher turbulence and fractures where Android is still going strong.</p>
<p>The main selling point for me on the Milestone was the massive screen size, and the positive reviews of its screen size; both of which, in practice, have been fabulous. I was holding out for a glimpse of the <a href="http://exchange.telstra.com.au/2010/08/12/telstra-unleashes-htc-wildfire/">HTC Wildfire pricing</a>, but I decided I didn&#8217;t want a tiny 240&#215;320 screen no matter how cheap it was.</p>
<p>The version I got was a UMTS 900/2100, which means it is not Next G compatible (which needs UMTS 850/2100). As I&#8217;m a Telstra user, that consequently means my coverage is not too crash hot. However, I could fix that simply by moving to Optus.</p>
<p>I&#8217;m not going to write a full-on review of the phone &#8212; there are plenty out there already. Any more you hear from me about this phone will be something I&#8217;ve hacked up for, hopefully, you to try.</p>
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		<slash:comments>2</slash:comments>
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		<item>
		<title>Enable caching in collectd!</title>
		<link>https://jeremy.visser.name/2010/02/23/enable-caching-in-collectd/</link>
		<comments>https://jeremy.visser.name/2010/02/23/enable-caching-in-collectd/#comments</comments>
		<pubDate>Mon, 22 Feb 2010 21:32:33 +0000</pubDate>
		<dc:creator>Jeremy</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[howto]]></category>
		<category><![CDATA[Linux]]></category>

		<guid isPermaLink="false">http://jeremy.visser.name/?p=1413</guid>
		<description><![CDATA[If you decide to run collectd on your system, don&#8217;t do what I did: I ran it for 8 months without caching enabled. Basically, that means that not only was collectd monitoring load, it was generating a huge amount of load itself — way more than anything else running on the system. Case in point: [...]]]></description>
			<content:encoded><![CDATA[<p>If you decide to run <a href="http://collectd.org/">collectd</a> on your system, don&#8217;t do what I did: I ran it for 8 months without caching enabled. Basically, that means that not only was collectd monitoring load, it was generating a <em>huge</em> amount of load itself — way more than anything else running on the system.</p>
<p>Case in point:</p>
<p><img src="http://jeremy.visser.name/wordpress/wp-content/uploads/2010/02/collectd-load.png" alt="collectd load graph. &quot;No caching&quot; shows high iowait, while &quot;CacheTimeout&quot; and &quot;CacheFlush&quot; shows the CPU load more than halved." title="collectd load" width="497" height="277" class="aligncenter size-full wp-image-1414" /></p>
<p>The &#8220;no caching&#8221; bit is what it&#8217;s been running like for 8 months, using this config in <code>/etc/collectd/collectd.conf</code>:</p>
<blockquote><pre>&lt;Plugin rrdtool&gt;
        DataDir "/var/lib/collectd/rrd"
&lt;/Plugin&gt;</pre>
</blockquote>
<p>To more than half my idle CPU usage, and get my load averages back down to near 0.00, all I had to do was add:</p>
<blockquote><pre>&lt;Plugin rrdtool&gt;
        DataDir "/var/lib/collectd/rrd"
<strong>       CacheTimeout 120
       CacheFlush 900</strong>
&lt;/Plugin&gt;</pre>
</blockquote>
<p>I don&#8217;t get why they don&#8217;t ship it like that by default. Enable caching. Your server will thank you. Thanks to the folks on <em>#slug</em> who held my hand while fixing this. <img src='https://jeremy.visser.name/wordpress/wp-content/plugins/tango-smilies/tango/face-smile.png' alt=':)' class='wp-smiley' /> </p>
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		</item>
		<item>
		<title>SCLUG site redesigned</title>
		<link>https://jeremy.visser.name/2010/02/21/sclug-site-redesigned/</link>
		<comments>https://jeremy.visser.name/2010/02/21/sclug-site-redesigned/#comments</comments>
		<pubDate>Sun, 21 Feb 2010 00:36:37 +0000</pubDate>
		<dc:creator>Jeremy</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[design]]></category>
		<category><![CDATA[Linux]]></category>
		<category><![CDATA[web]]></category>

		<guid isPermaLink="false">http://jeremy.visser.name/?p=1404</guid>
		<description><![CDATA[The South Coast Linux Users Group (SCLUG) website has had a lick of paint by yours truly. The old site didn&#8217;t look bad (in particular, I liked the penguin header image), but was getting a little long in the tooth, had a few issues (such as broken category styles, and images being linked to the [...]]]></description>
			<content:encoded><![CDATA[<p>The South Coast Linux Users Group (SCLUG) website has had a lick of paint by yours truly.</p>
<p>The old site didn&#8217;t look bad (in particular, I liked the penguin header image), but was getting a little long in the tooth, had a few issues (such as broken category styles, and images being linked to the wrong domain), and didn&#8217;t really reflect much about Wollongong, which is where we are based.</p>
<p>So a little <a href="http://www.inkscape.org/">Inkscaping</a> later, I came up with <a href="http://www.sclug.asn.au/">this</a>:</p>
<p><a href="http://www.sclug.asn.au/"><img src="http://jeremy.visser.name/wordpress/wp-content/uploads/2010/02/sclug.png" alt="SCLUG site in Wollongong livery" title="SCLUG thumbnail" width="300" height="291" class="aligncenter size-full wp-image-1409" /></a></p>
<p>Check it out. No, like, seriously. <a href="http://www.sclug.asn.au/">Check it out</a>. A bit more polish to come, but the idea is there.</p>
]]></content:encoded>
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		<slash:comments>1</slash:comments>
		</item>
		<item>
		<title>Source IP weirdities with irssi and IPv6</title>
		<link>https://jeremy.visser.name/2010/01/28/source-ip-weirdities-with-irssi-and-ipv6/</link>
		<comments>https://jeremy.visser.name/2010/01/28/source-ip-weirdities-with-irssi-and-ipv6/#comments</comments>
		<pubDate>Thu, 28 Jan 2010 12:08:06 +0000</pubDate>
		<dc:creator>Jeremy</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[aargh]]></category>
		<category><![CDATA[IPv6]]></category>
		<category><![CDATA[Linux]]></category>

		<guid isPermaLink="false">http://jeremy.visser.name/?p=1359</guid>
		<description><![CDATA[I&#8217;m having a weird problem with irssi and IPv6. The long and the short of it is that irssi is trying to connect to an IRC server on the Internet with a source IP address of ::1, which is incorrect, as ::1 is the loopback address. My server, glenstorm, is the IPv6 router, which contains [...]]]></description>
			<content:encoded><![CDATA[<p>I&#8217;m having a weird problem with irssi and IPv6. The long and the short of it is that irssi is trying to connect to an IRC server on the Internet with a source IP address of <code>::1</code>, which is incorrect, as <code>::1</code> is the loopback address.</p>
<p>My server, <em>glenstorm</em>, is the IPv6 router, which contains the <code>ppp0</code> interface that connects it to the IPv6 Internet. I am also running irssi on the same machine. It&#8217;s a router, so <code>/proc/sys/net/ipv6/conf/all/forwarding</code> is <code>1</code>.</p>
<p>So, basically, when I fire up <code>irssi</code>, and type &#8220;<code>/connect irc.ipv6.freenode.net</code>&#8220;, it hangs when connecting. And for good reason: here&#8217;s the (edited for clarity) <code>tcpdump</code> output:</p>
<blockquote>
<pre>IP6 ::1.34823 &gt; 2001:19f0:feee::dead:beef:cafe.6667
IP6 ::1.34823 &gt; 2001:19f0:feee::dead:beef:cafe.6667
IP6 ::1.34823 &gt; 2001:19f0:feee::dead:beef:cafe.6667</pre>
</blockquote>
<p>So obviously that&#8217;s wrong. And in violation of <a href="http://www.ietf.org/rfc/rfc4291.txt">RFC 4291</a>, I might add (&#8220;The loopback address must not be used as the source address in IPv6 packets that are sent outside of a single node.&#8221;).</p>
<p>I can hack around it by typing &#8220;/connect -host 2001:44b8:7df3:b970::14 irc.ipv6.freenode.net&#8221; into irssi, which forces it to use the source IP that I specified. But that&#8217;s just a hack — I&#8217;d like to get to the bottom of what actually causes it.</p>
<p><strong>Update:</strong> Finally solved this. It&#8217;s because in my irssi config, I had the following directive:</p>
<blockquote>
<pre>core = {
    <strong>host = "glenstorm";</strong>
};</pre>
</blockquote>
<p>It was being told to use &#8220;glenstorm&#8221; as the &#8220;host&#8221;, which translates to &#8220;resolve the IP address of glenstorm and use that as the source IP address&#8221; (I think I misunderstood the meaning of the directive when I put that configuration flag in).</p>
<p>Of course, in <code>/etc/hosts</code>, I had the following entry:</p>
<blockquote>
<pre>::1 glenstorm</pre>
</blockquote>
<p>So, naturally, irssi decided to use <code>::1</code> as the source IP address. So removing the &#8220;host&#8221; line from the irssi config fixed the problem. While I&#8217;m sure that because of the aforementioned RFC, that shouldn&#8217;t have resulted in the subsequent symptoms, at the end of the day, it was simply Unix allowing me to shoot myself in the foot.</p>
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		<slash:comments>3</slash:comments>
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		<item>
		<title>No DRI on X.Org with a Radeon? Check your Virtual size.</title>
		<link>https://jeremy.visser.name/2009/10/28/no-dri-on-x-org-with-a-radeon-check-your-virtual-size/</link>
		<comments>https://jeremy.visser.name/2009/10/28/no-dri-on-x-org-with-a-radeon-check-your-virtual-size/#comments</comments>
		<pubDate>Wed, 28 Oct 2009 03:52:25 +0000</pubDate>
		<dc:creator>Jeremy</dc:creator>
				<category><![CDATA[Uncategorized]]></category>
		<category><![CDATA[ati]]></category>
		<category><![CDATA[emac]]></category>
		<category><![CDATA[fedora]]></category>
		<category><![CDATA[hacks]]></category>
		<category><![CDATA[Linux]]></category>
		<category><![CDATA[xorg]]></category>

		<guid isPermaLink="false">http://jeremy.visser.name/?p=1303</guid>
		<description><![CDATA[After I installed Fedora Rawhide on the eMac this week, I fired up X.Org, only to discover that&#8230; (II) AIGLX: Screen 0 is not DRI2 capable (II) AIGLX: Screen 0 is not DRI capable So it had fallen back to a software 3D renderer, which is pretty crap. So to make a long story short, [...]]]></description>
			<content:encoded><![CDATA[<p>After I installed Fedora Rawhide on the eMac this week, I fired up X.Org, only to discover that&#8230;</p>
<blockquote><pre>(II) AIGLX: Screen 0 is not DRI2 capable
(II) AIGLX: Screen 0 is not DRI capable</pre>
</blockquote>
<p>So it had fallen back to a software 3D renderer, which is pretty crap. So to make a long story short, it was because my &#8216;Virtual&#8217; screen size was too big. I typed <code>xrandr</code>, and got the following:</p>
<blockquote><pre>$ xrandr
Screen 0: minimum 320 x 200, current 1280 x 960, <strong>maximum 2048 x 2048</strong></pre>
</blockquote>
<p>Because of various technical reasons, when the Virtual size is too big (which, evidently, 2048&#215;2048 is), DRI gets disabled. So, to re-enable it, I put this into my xorg.conf:</p>
<blockquote><pre>Section "Screen"
        Identifier "Main Screen"
        Device "Radeon 7500"
        Monitor "eMac CRT"
        SubSection "Display"
                <strong>Virtual 1280 960</strong> # put the highest resolution you intend to use here
        EndSubSection
EndSection</pre>
</blockquote>
<p>Obviously, edit the values to suit.</p>
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