02.02.2012 (February 2, 2012)

Fix accidentally misclick putty paste with irssi

Tired of pasting a bunch of lines into your irssi by a right mouse button misclick? Well, no more! Set these two irssi settings and irssi will ask you every time if you try to paste an entire line, or more. /set paste_detect_time 5msecs /set paste_verify_line_count 1 /save And that’s it!

20.01.2012 (January 20, 2012)

Adding new storage tank with diskmap.py.

We recently added a bunch of Western Digital 3.0TB Green drives to the enclosure, so that we can run a bunch of tests with this brand. Here’s a quick recap what I had to do to make these new disks online.

I just recently built a storage server based on Solaris OpenIndiana with SuperMicro 45 disk enclosure. The current configuration can host 84 TB of usable disk space, but we plan to extend this at least to 200TB in the following months. This blog entry describes the configuration and steps how to implement such beast by yourself.

I’ve just deployed a OpenIndiana storage system which uses a SuperMicro JBOD SC847E16-RJBO 45 disk enclosure and an LSI Logic SAS 9205-8e HBA controller with OpenIndiana (build 151a).

12.05.2011 (May 12, 2011)

Frontend Finland Presentation online

I had the privilege to do a presentation at yesterdays (2011-05-11) Frontend Finland event. Thanks for everybody who had the time to listen my presentation even when the time was a bit late. I’ve uploaded my slides so you can download them (PDF). Remember to check our career page if you would like to work with [...]

I’ve been experimenting with a Multi Level Security implementation in Windows 7 using VirtualBox and VMLite to run Chrome and other browsers inside a virtual machine (guest system) and to use this browser as the default browser for the entire computer (host system) for additional security.

Törmäsin asennusongelmiin Saunalahden mobiilitikun ohjelmiston kanssa yrittäiessäni asentaa sitä OS X:ään (10.6.5). Asennusohjelma ilmoitti virheen “An internal error has occured during configuration (5370)”. Ongelma voidaan ratkaista seuraavasti…

Are you a sysadmin who is new to Java? Then you might find this post to be helpful. Java has its own memory management system with garbage collection which is most of the time really nice, but you need to know some details how it works so you can admin your JVM instances effectively.

I’ve just created a zabbix template with a script which can be used to feed performance data from haproxy to zabbix. The script firsts uses HTTP to get the /haproxy?stats;csv page, parses the CVS and uses zabbix_sender command line tool to send each attribute to the zabbix server.

We had a situation where our image thumbnail memcached cluster somehow got empty thumbnails. The thumbnails are generated on the fly by image proxy servers and the thumbnail is stored into memcached. For some reason some of the thumbnails were truncated. As I didn’t have time to start debugging the real issue, I quickly wrote this oneliner which detects corrupted thumbnails when the thumbnail is fetched from the memcached and issues a delete operation to it.

01.10.2010 (October 1, 2010)

Open BigPipe javascript implementation

We have released our open BigPipe implementation written for IRC-Galleria which is implemented by loosely following this facebook blog. The sources are located at github: https://github.com/garo/bigpipe and there’s an example demonstrating the library in action at http://www.juhonkoti.net/bigpipe. BigPipe allows speeding up page rendering times by loading the page in small parts called pagelets. This allows browser to [...]

28.09.2010 (September 28, 2010)

How NoSQL will meet RDBMS in the future

The NoSQL versus RDBMS war started a few years ago and as the new technologies are starting to get more mature it seems that the two different camps will be moving towards each other. [read more...]

26.09.2010 (September 26, 2010)

Good analysis paper over Stuxnet worm

The W32.Stuxnet worm has raised quite much discussion as its been analysed and technical details about its construction has been revealed. Stuxnet is special because it’s very complex and its targeted to attack very specific set of industrial process computers. These and other worm characteristics hints that the worm was created by a government  sponsored virus laboratory. Some [...]

We have built a facebook style “messenger” into our web site which uses cassandra as storage backend. I’m describing the data schema to server as a simple example how cassandra (and nosql in general) can be used in practice…

23.09.2010 (September 23, 2010)

Cassandra operation success ratio survey results

It’s known that in Cassandra the compaction hurts the node performance so that the node might miss some requests. That’s why it’s important to handle these situations and the client needs to retry the operation into another working host. We have been storing performance data from each cassandra request which we do into our five [...]

09.01.2009 (January 9, 2009)

Hotswapping disks in OpenSolaris

Adding new SATA-disks to OpenSolaris is easy and it’s done with cfgadm command line util if the disk is in a normal ACPI SATA controller. I have also an LSI SAS/SATA controller SAS3081E-R which uses its own utils. Read more how to hotplug new disks with it…

OpenSolaris 2008.11 has a faulted e1000g driver which results in very poor upload performance. There’s a workaround which involves getting older version of the driver…

03.07.2008 (July 3, 2008)

Hosting virtual machines on Solaris

Hosting virtual machines inside an OpenSolaris box is very easy with VirtualBox. Here’s a quick tutorial how to install an ubuntu into a virtual machine which will take about 30 minutes of your time.

ZFS koostuu yhdestä levypoolista (storagepool). Levypool voi sisältää yhden tai useampia tiedostojärjestelmiä, jotka jakavat yhdessä koko levypoolin tilan. Tiedostojärjestelmien luonti on helppoa ja kevyttä, eli esimerkiksi jokaiselle käyttäjälle voidaan helposti luoda oma tiedostojärjestelmä. Tiedostojärjestelmät voivat muodostaa hierarkioita, tiedostojärjestelmille voidaan asettaa tilarajoituksia (quota), varata tietty miminimäärä tilaa (reserve space) ja tiedostojärjestelmiä voidaan jakaa (export) helposti esimerkiksi [...]

I had some bad performance problems with my new NAS box running ZFS which resulted terrible video and audio lagging problems in windows when I tried to stream video from zfs share via CIFS to a media player running in windows. Even playing mp3 music files from CIFS share in Winamp resulted with very bad [...]

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