Author Archive
EC2 Reserved Instances
Posted by Lars Schenk in Virtualisierung on März 16th, 2009
With “Reserved Instances” Amazon introduced an additional pricing option for EC2 that gives an option to make a one-time payment for an instance to reserve capacity and further reduce hourly usage charges. You may look up the details at: aws.amazon.com/ec2/#pricing.
I have made a rough comparison for the classic “on demand” small instance against the new reserved instance:
On Demand Instance:
$0 + (365*24*$0,10) = $876/year = $73/month
Reserved Instance 1year:
$325 + (365*24*$0,03) = $588/year = $50/month
Saves you $288/year or $24/month.
Reserved Instance 3years:
$500 + (3*365*24*$0,03) = $1288/3years = $430/year = $36/month
Saves you 446 $/year or 37$/month.
Here’s the offical FAQ on using Reserved Instances. And here’s a funny but critically blog post about the “single commandline that can costs you losts of money“. I think Marc Musings is right and I wish that Amazon would improve this because I had the same bad emotions with this “new API feature”. It would basically a good idea to have alerts and/or limits for charges, instances and traffic.
Can’t wait for reserved Instances to be available for the EU region… “in the near future” as Amazon promised… Happy emotions when spending big money with ec2-purchase-reserved-instances-offering!
UPDATE 09-08-21: New Lower Prices for Amazon EC2 Reserved Instances and I’m also happy to see that one of my EC2 instance hit the 500 days uptime mark.
“Waiting for root file system” caused by out dated VMware Server
Posted by Lars Schenk in Linux on Februar 25th, 2009
I run into a strange problem when I upgraded some VMs from Debian Etch to Lenny. I’m using VMware Fusion on my MacBook Pro and VMware Server on my local Debian Server. Upgrading VMs hosted by the VMware Server ended in System boot hangs “Waiting for root file system”. Upgrading nearly the same Etch VMs hosted by VMware Fusion did not fail.
According to Debians Upgrade instruction and it’s “How to recover” section, the problem can be caused by new naming conventions for IDE disks.
This problem can occur when the upgrade of the kernel introduces the use of the new generation of IDE drivers. The IDE disk naming convention for the old drivers was hda, hdb, hdc, hdd. The new drivers will name the same disks respectively sda, sdb, sdc, sdd. The problem appears when the upgrade does not generate a new /boot/grub/menu.lst file to take the new naming convention into account. During the boot, Grub will pass a system root partition to the kernel that the kernel doesn’t find.
This seems like to be very common reason for these “Waiting for root file system” troubles that many faces now when upgrading to Lenny. But in my case I allready had the new sda* names in the grub/menu.lst and /etc/fstab. The “solution to recover” did not work.
The virtual lenny server with the new kernel images that fails to boot was hosted by VMWare Server 1.0.3. For a nearly the same upgrade process (etch to lenny) hosted on FMWare fusion 2.0.2, I did not have these problems.
Solution: My VMWare Server 1.0.3 was out of date and had a known vmware bug that caused this error. Upgrading to the latest version (now 1.0.8) solved the problem.
Nagios commands via web-interface on Debian
Posted by Lars Schenk in Linux, Open Source, tech-recipes on Februar 24th, 2009
Ups, I did it again – when I upgraded to Debian GNU/Linux 5 (lenny) and Nagios3 I stumbled about this nagios error when I try to send directs commands via the web-interface:
Error: Could not stat() command file ‘/var/lib/nagios3/rw/nagios.cmd’!
In “/etc/nagios3/nagios.cfg” the “check_external_commands=1″ was already set. So there was something more required to make it run on Debian…
Deep in my memory I know that there was a debian way to solve this user right related problem. This time I’ll write it down here – perhaps I’ll find it more easily when I upgrade to Debian GNU/Linux 6.0 (codenamed squeeze) and/or Nagios4.
/etc/init.d/nagios3 stop
dpkg-statoverride –update –add nagios www-data 2710 /var/lib/nagios3/rw
dpkg-statoverride –update –add nagios nagios 751 /var/lib/nagios3
/etc/init.d/nagios3 start
Cloud Computing – DLD09
Posted by Lars Schenk in Video, Virtualisierung on Januar 28th, 2009
If I had to convince a non technical person about Cloud Computing, I would show him this video.
I really enjoyed listening to Dr. Werner Vogels. Dr. Vogels is Vice President & Chief Technology Officer at Amazon.com where he is responsible for driving the company’s technology vision, which is to continuously enhance the innovation on behalf of Amazon’s customers at a global scale.
This vision is why I have moved to EC2/S3 in 2007. I guess, I’ve finally become an Amazon AWS fan boy.
Even if audio is a bit out of sync, it’s worth to listening this long session.
As a developer from the bottom of my heart I like especially this quote: “There is no value in being a system administrator. You do not build a better product by being a better server maintainer.” This is so true, but I wonder how EC2 can free me from typical administration tasks. I still have to maintain my virtual server instances with the whole LAMP stack. Plus I have to think about how to scale horizontally (what to do when I need more virtual server instances).
In contradiction to Amzon’s EC2, Google’s AppEngine promises to free me from doing the admin tasks (no OS/LAMP Stack to maintain) and to solve the scale problem (no Database Replication to set up). AppEngine scales out of the box – the downside is, that it offers a very limited runtime just for you app.
True, a single EC2 instance doesn’t scale out of the box but it also doesn’t limit you in doing what you want to do on your virtual server. With EC2 I have to solve the scaling on my own. For this price I got more freedom.
I’m exited to use and learn about EC2/S3/Storefront each day but I also hope that Google’s AppEngine will offer a wider range of runtime environments in the future. t’s an interesting Cloud-Year 2009! #buzzword
So funktioniert der Apple Automator
Posted by Lars Schenk in Apple, Video, osx, tech-recipes on Januar 19th, 2009
Der Automator in OS X ist ein sehr nützliches Tool zum automatisieren von Routineaufgaben. Komplexe Arbeitsabläufe lassen sich zum wiederholten Anwenden zusammenstellen. Viele Anwendungen wie Finder, iTunes, Safari, iPhoto, Mail, iCal usw. lassen sich sehr leicht über den Automator nutzen so dass i.d.R. nicht einmal mehr eine einfache Scriptsprache wie z.b. AppleScript erforderlich ist um wiederkehrende Aufgaben in einer Art Minianwendung zusammenzufassen.
Ich glaube viele Apple Benutzer kennen das Tool aber nicht oder können vielleicht nicht viel damit anfangen. Vielleicht ändert sich das nun, denn Lars Blumberg erläutert in seinem wunderschön gemachten Screencast sehr anschaulich die Bedienung und Funktionsweise des Apple Automators. Da dieses Video im Rahmen eines Seminars “End user programming” entstanden ist, geht Lars Blumberg zu Beginn auf das Pipe-Konzept ein auf dem der Automator beruht, bevor ein Beispiel erläutert wird.
Im dritten Teil des Screencasts wird die Programmierung einer eigenen Erweiterung (Action) für den Automator mit Xcode demonstriert. Alle Schritte sind in dem liebevoll gemachtem Video ausführlich dokumentiert, so dass ich hoffe dass Anwender und Scripter neugierig gemacht werden sich einmal etwas ausführlicher mit Apples Automator auseinander zu setzen.
So funktioniert der Apple Automator from Lars Blumberg on Vimeo. (c) 2008 Lars Blumberg
Welchen DAC/KHV an Toslink: Citypulse, Zhaolu, Tianyun Zero, Audio Technika?
Posted by Lars Schenk in Musik, Persönliches, tech-recipes on Januar 17th, 2009
Um den wirklich sehr schlechten Analog-Ausgang des MacBook Pro zu umgehen (es rauscht und fieps; man hört eher das LogicBoard als die Musik – für ein AppleProdukt nicht akzeptabel ja sogar katastrophal; zumal das Vorgängermodel da deutlich besser war. read the full story here) möchte ich auf den optischen Ausgang ausweichen.
Folgende Geräte (allesamt mit optischen Input) für den nicht mobilen Einsatz hatte ich dabei im September 2008 in die engere Wahl gefasst: Read the rest of this entry »
OMG this is so funny, I need to share this.
Posted by Lars Schenk in Video on Januar 15th, 2009
Watch White & Nerdy in HD from waymoby on Vimeo.
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