Entries by Joerg Moellenkamp

In some discussions in mail and in some community forums linking to the articles about deduplication and hashing there was a slight misunderstanding. I should explain some things.

There was some discussion about possible attack vectors for checksum-only deduplication. However i don't think the proposed vectors are really feasible. The first attack tries to create data corruption by foiling deduplication into using a thoughtfully created block, with the same checksum but different data. Another, less discussed attack vector, is gaining knowledge of a block by using a thoughtfully created block to foil dedup to show you a different block than the one you have actually written, as the checksum-only variant didn't stored your block, but just created a pointer to data written beforehand.

Humans have a design flaw, they don't have a sense for risks. When you look at the risks from a more scientific perspective, the probability of dying in a terror attack is vastly lower than the probability of dying because you've committed suicide. With a realistic view to the risks, you should look in the mirror each day and observe yourself, not to other peoples in the aircraft, the subway or somewhere else. However the fear-mongers were able to implant us other feelings and so we strip-search people looking differently from us, we even start to strip-search everybody by technology like backscatter scanners.

Why do i talk about this? Well ... there is an technology in ZFS, that allows you to work with probabilities to speed up things. It's the deduplication part. You can use it in a way, that doesn't verify bit-for-bit if a block is really identical to another before just storing a pointer to the already stored block.

There is an interesting read at the Seek Alpha website. They published the Oracle+Sun Strategy Update Analysts call as a transcript. Gives some interesting information about the plans to make Sun's business profitable in year 1.

The usual suspect announced the second beta of the upcoming Virtual Box 3.1.4. You can download the beta here. As you may recognize while looking at the changelogs of Beta1 and Beta2, the 3.1.4 release is dominated by fixes instead of new features.

Wann immer eine neue Technologie auftaucht, ist es mittlerweile Usus, diesen zum Grund für den Untergang der Zivilisation hochzustilisieren.

Jonathan Schwarz announced his last day at Sun with this tweet roughly an hour ago:

Today's my last day at Sun. I'll miss it. Seems only fitting to end on a #haiku. Financial crisis/Stalled too many customers/CEO no more

Of course it's a little bit tedious to zip cables from your switch to test IPMP or to deconfigure an interface to force traffic on different interfaces when you want to do some maintainance work in your network. There is an command to on- and offline physical connections in an IPMP group. It's called if_mpadm.

Unbeknownst to many people (including me), IKEA sells a modular rack system. A colleague hinted me to correct product at the IKEA website.. The product name is LackRack. For further technical indepth information you should visit this website of a IKEA rack customer. Albeit i don't think this rack will have a high "Significant Other Acceptance Factor", it's surely better than the one of a full size Sun rack in the living room.

Am 4.3.2010 findet in der Sun Geschäftsstelle Hamburg das 10. HHOSUG Meeting statt. Die Agenda steht noch nicht ganz fest, aber wenn nichts dazwischen kommt wird es wohl einen Vortrag über vi und einen Vortrag zum Thema "Urheberrecht für Entwickler" geben. Ich denke, das ich auch noch einen Solaris-Kurzvortrag machen werde, habe mich da thematisch aber noch nicht festgelegt. Um genügend Pizza zu bestellen, bitte ich um Anmeldung via Xing oder via Mail an hhosug10@joerg.moellenkamp.org.

When you work with the interesting features of Solaris, you forget about the small features in commands you use day by day. In my my IPMP tutorial i used an SMF script to make some host routes persistent ... at foremost to show you that SMF scripts are really easy. But, well ... this script isn't nescessary because of the -p option of the route add command.

Looks like, Tukwila was released. Intel PR writes:

"Tukwila," the code name for the newest Itanium processor, has begun revenue shipments. The most advanced Itanium processor yet, "Tukwila" more than doubles the performance of its predecessor and adds a range of new scalability, reliability, and virtualization features

Just three years late

The Power7 launch may be imminent, too. IBM invited to a series of events in Germany on this webpage. There is an event called "IBM POWER Vorstellung" and the headline is "Experience the next generation at the POWER event ...". Don't think, they will just announce a speed bump. And i was told, an earlier version of the page contained the 7. I'm really interested, if they will announce some prices (the Power7 is a large beast as far as i know, will be expensive), benchmarks (still thinking that the single thread will be slower, than at Power6 ... well ... Power7 is IBMs implementation of the basic CMT idea: more cores, but simpler cores ... no offence in this statement ) and if they will announce upgrade paths for older systems.

Will be nice to make some competitive comparision based hard numbers, not just on informed assumptions.

Am 26. Februar findet in Kiel wieder die alljährliche NetUSE Hausmesse NUBIT statt. Im Rahmen dieser Veranstaltung werde ich von 16:30 bis 18:30 einen Vortrag zum Thema "Solaris Secrets reloaded - noch mehr wenig bekannte Features von Solaris" halten.

One of the interesting features of Solaris x86 missing in the SPARC variant is the support for fast reboot. Fast reboot reduces the boot times, as it skips firmware and boot loader. The old kernel loads the new kernel and passed the control to the new one. With PSARC 2010/030 the SPARC variant of Solaris will get fast reboot, too.

Hier stand bis heute morgen die Ansprache, die ich für meine Oma geschrieben habe. Ich habe einige Mails bekommen, die das gut fanden, ich habe einige Mails bekommen, die das nicht so toll fanden. Da aus meiner Sicht der Blogeintrag die hinter der Veröffentlichung stehende Intention erfüllt hat, habe ich ihn nun entfernt. Dem Andenken an meine Oma ist Rechnung getragen. Der Teil des Vortrages, den ich veröffentlicht habe, war meine Beschäftigung mit dem Thema Tod, Erinnerungen, über das Vermissen. Der andere Teil war Privat, der in der Tat die Öffentlichkeit nichts angeht.

Ich möchte aber dies für eine Klarstellung nutzen: c0t0d0s0.org ist kein Technikblog.Es kommt vielen so vor, weil sie hier viele technische Dinge lesen. Dem ist aber nicht so. c0t0d0s0.org ist das Blog von Jörg Möllenkamp. Dieses Blog hat eigentlich kein Thema und ich behalte mir vor, ueber jedes Thema zu schreiben, das mir in den Sinn kommt. Wer das nicht lesen möchte, sei auf die Kategorien verwiesen, die dieses Blog thematisch untergliedern.

Ich habe mich irgendwann dafür entschieden eher weniger private Dinge hier zu schreiben, weil mich in meiner Nische einfach zuviele Menschen mittlerweile kennen. Ich bitte zu entschuldigen, das dennoch manche Ereignisse dennoch den bei mir so viele Emotionen hervorufen, die dazu führen, das ich dann doch den Weg ueber das Blog suche, um diesen Lauf zu lassen. Das kommt vielleicht ein oder zwei mal im Jahr vor. Letztes Jahr die Horrorwoche, dieses Jahr die Trauer.

Und ja: Ich bin ein Kind des Netzes. Mein erster Kontakt mit dem Internet war im Jahr 1992. Ich verwende es als natürlichen Teil meines Lebens.