Linux

Big grats to One, with its one year uptime. ;) And been running for over 1500 days ! Old server is getting old. :(

(The 2nd one from the top ;), resting on that Xserve)

This is an old dual P3 I got off eBay years ago. This blog is running on that server. It's running Gentoo as OS.

Next up is Four and about an hour after that Two! Geekyness!

Playing around and searching the web I enabled some decent caching now.

Here are some stats: image+html and php. Note that the php on apache (recompiled each request, about 1.5-2sec between every request) versus the cached output has a huge difference. Difference between images and static text files aren’t that huge. Also note that nginx has gzip enabled. The downside is that nginx caches all pages (HTTP code 200) for one hour and isn’t notified when pages are modified (yet).

The issue with the wrong IP address being shown when using nginx as reverse proxy can easily be solved with mod_rpaf.

vs

cache.blog.tuinslak.org 85.12.6.171 - - [22/May/2010:16:27:40 +0200] “GET /2010/05/nginx-reverse-proxy/ HTTP/1.0” 200 22639 “-” “Mozilla/5.0 (Macintosh; U; Intel Mac OS X 10_6_3; en-US) AppleWebKit/533.4 (KHTML, like Gecko) Chrome/5.0.375.53 Safari/533.4” 1771 23031

I’ve been playing around a bit with nginx and its reverse proxy module. The “real” website is accessible here, whereas the cached version is here.

I’m deliberately making a difference between cache.* and live.* as blog.tuinslak.* might move to the cached version lateron.

The question, is it useful to reverse proxy this blog? No, probably not. But meh… It’s fun. :)

IP differences between both versions: live vs cache°. I’m guessing as most of the stats (Google Analytics and WP Stats) are JavaScript based, all stats should still be correctly generated. Only the Apache logs show the nginx proxy IP address. Which is normal, I guess.

I recently migrated vm1 to nginx instead of lighttpd. Just for the sake of playing and testing around.

As there’s a PHP page as well, I had to set up fastcgi with PHP. I mainly followed this tutorial to try to get PHP working.

However, every PHP page I visited returned following error:

No input file specified.

As I was fairly sure it was path (or variable) related, I played around with:

Trying to recompile the VMware Server 2.0.2 on kernel 2.6.33 I came upon these two errors:

# uname -a Linux Sauron 2.6.33 #1 SMP Tue Mar 9 15:09:05 CET 2010 x86_64 AMD Opteron(tm) Processor 248 AuthenticAMD GNU/Linux

This is a Gentoo machine.

Error 1:

The directory of kernel headers (version @@VMWARE@@ UTS_RELEASE) does not match

your running kernel (version 2.6.33).  Even if the module were to compile

successfully, it would not load into the running kernel.

What is the location of the directory of C header files that match your running kernel? [/usr/src/linux/include]

This can be resolved by editing version.h (usually in /usr/src/linux/include/linux) and adding this line:

I recently started to notice following error messages on my openVPN server.

As I need to run OpenVPN using the TCP protocol (instead of the faster UDP protocol; as UDP is often blocked in networks I use my VPN in) I experimented by increasing the tcp-queue-limit. The default is 64, and I’ve set it to 256. So far, everything still seems to be working fine (but more packets will be queued before being dropped by OpenVPN, requiring less retransmissions).

I’ve had an issue for a while, being unable to access certain websites such as https://fon.com, but also certain parts of the Apple, Fortis and Microsoft site, while other (https) websites worked fine.

Running Wireshark I found that only about 5ish packets got transferred, and all other data to that website abruptly stopped.

I’m using ADSL (EDPnet), which has an MTU of 1492, however, I was able to access all websites from the router (using lynx, for example), but not from any other PC within the network.

If you’re running uptimed (or uprecords) and what to display it in a simple php page, you’ll notice the bold text makes the page somewhat ugly.

Use this file to remove the bold chars and make it readable.

Examples: zero, one, four, vm1, Sauron

Yesterday I’ve start using Prowl, as I heard good comments about it. And one of the things I want it to check, are my server statuses. I made a quick script using bash and crontab to check every 10 min if it replies on ping. Per server, I created “host.domain.tld.sh” (e.g. zero.rootspirit.com.sh), and added this in the file:

#!/bin/bash
KEY=YourApiKey
HOST=zero.rootspirit.com
ping -c 1 $HOST   &>/dev/null
if [ $? -ne 0 ] ; then
curl -k -s "https://prowl.weks.net/publicapi/add?apikey=$KEY&application=Server%20Connectivity%20Failure&event=&description=$HOST&priority=2"
fi

Of course, change KEY to your API key, HOST to the IP or DNS of the server it should ping. Also, make sure, that when pinging on your host where you’ll run the bash script on, a non-existing domain actually returns: