Juho Mäkinen's blog

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.

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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.

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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).

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Kindle on Amazonin erinomainen sähköisten kirjojen lukulaite, jonka saa tilattua Amazonin verkkokaupasta reilun sadan euron hintaan. Jenkkimatkalla Kindlen voi noustaa itselleen noin 70 euron hintaan…

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I’ve just uploaded my Pitfalls and Lessons Learned with node.js presentation slides from #ReaktorDevDay 2011 to http://www.juhonkoti.net/media/reaktordevday-juhomakinen-nodejs-2011-09-02.pdf.

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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 [...]

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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.

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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…

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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.

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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.

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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.

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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 [...]

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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...]

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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 [...]

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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…

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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 [...]

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One of my disks in a raidz2 array crashed a few days ago and it was time to hotswap a disk. zpool status showed a faulted drive: raidz2 DEGRADED 0 0 0 c3t6d0 ONLINE 0 0 0 c3t7d0 FAULTED 27 85.2K 0 too many errors c5t0d0 ONLINE 0 0 0 c5t1d0 ONLINE 0 0 0 [...]

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You all know this: You learn something new like a new word and then the next day you’ll stumble across this new thing you have just learned in a newspaper. Most of this can be easily explained with some brain pattern matching: you have previously come across this word many times but because you didn’t [...]

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Tänään tein: Kävin katsomassa Kalliossa yhtä kämppää. Vaatisi täydellisen pintaremontin ja hinta remontin kanssa menee budjettini ylitse. Tai menisi, jos tietäisin mikä budjettini on. Ainakin sain lisää kokemusta näytöistä :) Ostin koirakirjan! Koirien Pikkujättiläinen – Hoito, Kasvatus ja Rodut, Ulla Kokko, WSOY. Pistin myös sisäsivuille postit-lapun, jossa Bitey kieltää mua lukemasta sivuja 171 – 189 [...]

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Erinäisten vaiheiden jälkeen päädyin elämäni ensimmäistä kertaa asuntonäytöille. Olen toki lapsena käynyt yhdessä vanhempieni kanssa katsomassa uutta koko perheen asuntoa, mutta nyt menin katsomaan asuntoa yksin itselleni.  Ensimmäisenä kohteena oli Mäkelänkadulla sijaitseva 43m^3 kaksio. Bussipysäkki talon edessä ja takuulla tarpeeksi liikenteen ääniä pitkin kesää. Rappukäytävä oli vähän huonossa kunnossa, mm. alimmassa kerroksessa rapun alla oli jotain rojua [...]

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