The moment I heard about the Open Source Bridge Configuration Management panel session on FLOSS Weekly a while ago, I was hoping that I will be able to see the recording of this session (as for obvious reasons I was not able to attend and see this live in Portland, Oregon). They managed to bring together (for the first time to my knowledge) the creators (or maintainers) of *all* the major configuration management tools to date was very impressive; and obviously someone as myself that has been working with many of these tools (I haven’t tried/used automateit yet) would definitely see this as a great session.

Here are the members of the configuration management panel (from left to right):

• Igal Koshevoy of AutomateIt
• Brendan Strejcek of Cfengine
• Luke Kanies from Reductive Labs for Puppet
• Narayan Desai of bcfg2
• Adam Jacob from Opscode for Chef

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This post is sponsored by FindMyHosting - a free and very comprehensive web hosting directory featuring the most popular web hosting companies and thousands of customer reviews.

I’ve been asked to review this site and give my impressions about it. The truth is that I don’t have much experience with shared hosting as most of my experience is with dedicated servers from various hosting companies, and anytime I had a friend asking about where do I recommend him to host his small site I didn’t knew where to direct him. This is why I thought that such a webhosting directory as FindMyHosting would be a great start for anyone looking for a shared hosting account to host his new site. We can search from a long list of hosting company and get them ranked by users reports (nice). Read the rest of this entry »

The Debian project just announced the second update for its stable distribution “lenny” 5.0.2. Those installing regular updates from security.debian.org might not even notice this update, except for the version change to 5.0.2. As an interesting change, the debian-installer has been updated to allow the installation of the oldstable release (Debian 4.0 “etch”).

“The Debian project is pleased to announce the second update of its stable distribution Debian GNU/Linux 5.0 (codename “lenny”). This update mainly adds corrections for security problems to the stable release, along with a few adjustment to serious problems.
Please note that this update does not constitute a new version of Debian GNU/Linux 5.0 but only updates some of the packages included. There is no need to throw away 5.0 CDs or DVDs but only to update via an up-to- date Debian mirror after an installation, to cause any out of date packages to be updated.
…
New version of the debian-installer
The debian-installer has been updated to allow the installation of the previous stable release (Debian 4.0 “etch”) and to include an updated cdebconf package which resolves several issues with installation menu rendering using the newt frontend, including:
* explanatory text overlapping with the input box due to a height miscalculation
* overlapping of the “Go Back” button and the select list on certain screens
* suboptimal screen usage, particularly affecting debian-edu installations
The installer has been rebuilt to use the updated kernel packages included in this point release, resolving issues with installation on s390 G5 systems and IBM summit-based i386 systems.”

Release Announcement: http://www.debian.org/News/2009/20090627

I needed to get a list of all the subdirectories that were owner by some other user than root under /var and their permissions/owner with full paths. My first thought was to use ls and something like this:
ls -dlR */
drwxr-xr-x  2 root root  4096 2009-06-05 06:25 backups/
drwxr-xr-x  8 root root  4096 2009-05-11 06:02 cache/
drwxr-xr-x  2 root root  4096 2009-05-06 04:49 ec2/
drwxr-xr-x 25 root root  4096 2009-05-25 14:55 lib/
…
will show the subdirectories just as I needed but only at one level. Using */*/ would show the next level, etc. This obviously is not a solution and unfortunately I had found no other way to do this with ls. Using:
ls -alR | grep ^d
drwxr-xr-x 15 root root  4096 2009-05-11 06:02 .
drwxr-xr-x 22 root root  4096 2009-06-03 15:02 ..
drwxr-xr-x  2 root root  4096 2009-06-05 06:25 backups
drwxr-xr-x  8 root root  4096 2009-05-11 06:02 cache
drwxr-xr-x  2 root root  4096 2009-05-06 04:49 ec2
drwxr-xr-x 25 root root  4096 2009-05-25 14:55 lib
….
works somehow, but since I don’t have the full paths this is useless.

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The moment a PHP application grows to run on more servers, normally people will see problems caused by PHP sessions. If the application is not persistent you are lucky and don’t care about this, but if not you will quickly see this regardless of how good the load balancer you use is handling stickiness (sending the users to the same real server), this will slowly become a major issue. There are various solutions that can be used to store PHP sessions in a shared location, but I want to present today one solution that is very simple to implement, yet very efficient and on the long term better suited than using a database backend for this: using memcache to store the sessions.

The pecl memcache php extension has supported for a long time the memcache session.save_handler, but with the release 3.0.x (still in beta at this time) this brings in a set of interesting features for us:
- UDP support
- Binary protocol support
- Non-blocking IO using select()
- Key and session redundancy (values are written to N mirrors)
- Improved error reporting and failover handling

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A while ago one of the major problems people faced to use Amazon EC2 into production environments was the dynamic state of the instances IPs. Every time one instance was started it was getting a new, dynamic IP. This has been addressed with the introduction of Amazon Elastic IP Addresses, but even when using this, the private IPs are still dynamic and most of the time people will want to communicate between several instances on the private allocated IPs and not on the public ones. This article will show how you can easily automate the process to update DNS hostnames for your EC2 instances, by adding to the AMI’s the logic for this. I will use for this a master DNS server running bind9, but this can be adapted to any other DNS server. Read the rest of this entry »

My post “Debian Lenny PXE Installation on Dell PowerEdge 1950/2950 servers: bnx2 annoyances” got some attention and several people used the resulted initrd images. My intention with that post was to show anyone how they can easily build their own updated initrd and use it to successfully install Dell PE 1950/2950 (or other systems that have bnx2 based nic’s). Apparently several people used the images I’ve made available for download and when lenny was updated to 5.0.1 the images stopped working because of the kernel upgrade in the installer. Several people send me notices that this is no longer working and I promptly build updated images for i386 and amd64. I would like to thank to all the people to contact me about this and specially to Alexander Grümmer that showed me that my previous post was not clear enough with the commands needed to rebuild your own initrd. This post will show a full copy and paste type of commands for doing this. Read the rest of this entry »

Between 20-24 April 2009 I attended to CloudSlam09, the 1st annual virtual conference on cloud computing. This was a global event, using the webex technology, covering latest trends and innovations in the world of cloud computing. Being a virtual event it allowed me to easily attend and listen to several keynotes and talks from the comfort of my home/work office. Obviously this is a huge advantage as not so many people can leave their jobs for 1 week to go at such events. This was a great idea for such an event and a perfect match for the topic.

Besides the obvious advantages of a virtual event, I would like to outline also some disadvantages: besides a rather poor sound quality for some speakers, the biggest minus for me was the inability to focus on a single talk uninterrupted. This because, being actually at work I had to deal with all the usual stuff that I have to do normally (the ones called emergencies). Being on a real event would imply other type of ‘noise’ but anyway .

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Ubuntu released official images for Amazon EC2 for Intrepid (8.10) and Hardy (8.04) releases (not Jaunty image yet). These are server edition images. I’ve always used the great alestic ec2 images created by Eric Hammond for any Ubuntu or Debian release I needed in the past and was very happy with the quality of the images Eric maintained. This was also seen by the Ubuntu team and they worked with Eric to create their official images with the same quality and most of the features of what most people were used for Ubuntu images so far in EC2 world.

In my opinion here are the advantages of the newly released official Ubuntu images:

• officially support by Canonical (Eric has done a great job in patching and updating his images, but I am sure he has better things to do and let the Ubuntu team do this).
• custom kernels: for Intrepid 2.6.27 and Hardy 2.6.24 by having Amazon support in doing this (while alestic images were using the default Amazon Fedora kernel 2.6.21 image).
• apt mirrors in the ec2 cloud provided by Ubuntu: us.ec2.archive.ubuntu.com and eu.ec2.archive.ubuntu.com
• RightScale support for advanced integration with the RightScale platform for RightScale users.

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Just a few days after the eighth update of etch (4.0r8), the Debian project announced the first update of lenny. Opposed to the etch updates, this receives a minor numbering in the version 5.0.1 and also updates the /etc/debian_version file with this information; even if this is a simple change, I like it a lot as it will make it much easier to identify what update level a machine is running (just like redhat world had forever in /etc/redhat-release ). Besides this cosmetic change, most of the updates were already on security.debian.org; still there is a kernel update (minor version update of course) that fixes some openvz, nfs bugs (see debian kernel changelog for full details) and because of this also an updated debian-installer.

“The Debian project is pleased to announce the first update of its stable distribution Debian GNU/Linux 5.0 (codename lenny). This update mainly adds corrections for security problems to the stable release, along with a few adjustment to serious problems.

Please note that this update does not constitute a new version of Debian GNU/Linux 5.0 but only updates some of the packages included. There is no need to throw away 5.0 CDs or DVDs but only to update via an up-to-date Debian mirror after an installation, to cause any out of date packages to be updated.

Those who frequently install updates from security.debian.org won’t have to update many packages and most updates from security.debian.org are included in this update.”

Release Announcement: http://debian.org/News/2009/20090411