Bits and Chaos


Between bits and chaos, a sysadmin stands.

Why open source is a superior development tool: the Zmanda backup tool for MySQL

Free and Open Source is a lot more than a bunch of licenses: it’s a development model, a culture and an ecosystem, that every day and in many different and sometimes unexpected ways shows its inherent superiority. Plus, it’s free, and we’re happy when someone decides to embrace it and surfing the wave to build the next great system.

This story started some time ago, when I searched for a MySQL backup system, and I found Zmanda MySQL Backup.

I have used it for almost one year now, and I’m completely satisfied: it take minutes to configure, I’m using 10% of its features and it already does everything I need. During this year, I restored from a backup several times, retrieving a single database or the entire collection, and Zmanda did its job perfectly. It’s the kind of software you put in production and forgot it because it works.

So long this one would be the typical open source story, where an open source tool is the primary choice in a OSS environment: if you don’t put your money in the database, probably you won’t pay for a database backup system, which is somehow a second line system. The story goes interesting when I encounter a bug in Zmanda, which is a conflict with the required version of Perl.

Now take look at the last messages from the thread: I filed the bug and 3:09 am (I live in Italy and the message time are US-based, I’m not a fanatical bug hunter), and a fixed release was out at 10:09.

It takes 7 hour from bug filling to package release.

It’s a open source tool, we are not paying customers, but we get from the nice and caring people of Zmanda a fixed release for a not critical bug in less than one working day. You won’t get the same level of service from a corporate multibillion software vendor, granted.

This is way OSS is superior: it put the good people working together to build and fix. Everyone adds a small part, but this endless process finally result in a masterpiece.

Filed under: mysql, oss, , , , ,

VMware Server 2.0 beta: first impressions

I’ve eagerly downloaded and installed VMware Server 2.0 beta to test it, over my Fedora Core 6 (yes, when it comes to operating systems I’m a bit conservative). The machine is a AMD 64 3000+, with 1 GB RAM, that I’ve successfully used with the VMware 1.0.x series.

Competition in the arena of virtualization is today mostly on the management and support tools, because as the hardware support increases, the relative differences between hypervisors (being there binary translator a la VMware or para-virtualizer a la Xen) will be of less importance. AMD has the nested paging feature on the Barcelona series resulting in a lowering of TLB miss count. Intel has concentrated its efforts to obtain an efficient DMA mapping: the Intel VT-d technology will reduce the perfomance hits that a guest machine experiences every time it performs a I/O operation. These technologies will be first deployed by high-end consumers, but sooner or later they will land over final user desktop, so someday we’ll play all the Windows games over a Linux machine 🙂

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Filed under: virtualization, ,

Integration of Mongrel with RHEL and derivatives

(EDITED: You probably live a lot better using mod_passenger)

Mongrel is the Ruby on Rails application server. It’s not included in RHEL 4.x nor 5.x, so I wrote this little script to have it managed by the service command. If you’re used to Apache server, Mongrel is a bit different as it’s only an application server, and it’s mono-threaded. So if you want more than one instance working, you need to explicitly decides how many of them you want and on which port they will listen (one instance for one port). Mongrel works better as the back-end, on the front-end put Apache that will do a lot better work. The script I’m describing in this blog entry is for automatic starting/stopping of this instances, integration with Apache will be described in another entry.

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Filed under: rhel, ruby on rails, , , , , ,