Munin/rrdtool spike removal

Occasionally I see spikes on my network card charts. I found this article which says how to remove them and basically it shows how to convert the rrd file to xml and vice versa, so it's worth remembering.

cd /var/lib/munin/HOSTNAME

# To export rrd file to xml, use
rrdtool dump file.rrd > file.rrd.xml

# Move the rrd file to backup
mv file.rrd file.rrd.bak

# To convert from xml to rrd, use:
rrdtool restore -r file.rrd.xml file.rrd

# In case running under different user (e.g. root), don't forget to change back the ownership of rrd files:
chown munin:munin file.rrd

# To regenerate graphs, run as munin:
/usr/share/munin/munin-graph --nolazy --host $HOSTNAME --force

mycal2rem

I was using ical2rem.pl to pull data off my Google calendar and display it in wyrd, which I'm using on my laptop. After a while I found a few shortcomings:
- the parsing of the .ics file from Google took about 25 seconds (on my Intel CoreII Duo T7100) during which the CPU was fully utilized
- the script does not use the features of remind format, e.g. the repeating events are created as multiple entries in the remind file

The mycal2rem.pl is far from full implementation of the .ics format (RFC 5545), but currently it parses all events from my calendar just fine.

The script can be found at github.

fail2ban

I am quite happy user of denyhosts for my server.
However, I started to look for a solution that is able to block access to other services as well. And I discovered fail2ban.
I am using it to block access to my ssh server and also my apache server, because there is a few queries for the phpmyadmin etc.
There were a few issues with stock fail2ban, namely What are fail2ban's log iptables “returned NNN” entries? (Fail2ban is failing to ban) and fail2ban startup iptables error.
Another problem is that the banned IPs are lost on fail2ban restart. I managed to fix that somehow bu exporting the list of banned IPs on service stop and importing it back again on service start. I even posted the way to export banned IPs to the wiki

#!/bin/sh
jails=$(fail2ban-client status | grep Jail\ list: | sed 's/.*Jail list:\t\+//;s/,//g')
for jail in ${jails}; do
    for ip in $(fail2ban-client status ${jail}|grep IP\ list|sed 's/.*IP list:\t//'); do
        echo "fail2ban-client set ${jail} banip ${ip}"
    done
done

So far it works fine for me.

Converting AVCHD Videos (part 2)

Recently I tried to use ffmpeg to convert AVCHD to mp4. However I experienced sound issues and I discovered the default audio bitrate was used (64k). I needed to enhance the command to:

ffmpeg -i $1 -sameq -ab 192000 -f mp4 $1.mp4

This is on Ubuntu 11.04 x86_64.

How to un-break graphical Java apps under Ratpoison

Finally, the ultimate solution.
Thanks!

Dropbox

I wanted to start using my Ubuntu One on my Debian server. Instead I tried out Dropbox. The installation is straightforward, I followed this guide. I needed to update the init.d script a little (I even updated the wiki @ Dropbox site).
I plan to use my account to store backups of my SVN repository, it's very small at the moment so the free 2GB quota should be enough for me. I will create a script that will compress, encrypt and store the SVN repo to Dropbox.

Update to Squeeze

Just updated to Squeeze. No issues so far, only munin got relocated from /var/cache/munin/www to /var/www/munin .