Network: April 2008 Archives

Neon : Take Three

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Alright - it turns out the RocketRAID is both a snare and a delusion.


  • The claims of hardware RAID are simply false - all processing is pawned off onto the system CPU.

  • The 'open-source drivers' are actually open-source wrappers for closed-source drivers. In either event, they're impossible to slip stream during OS installation.

  • Supports every major linux distro my ass.


So.....we've since purchased an LSI MegaRAID 150-6 RAID controller. I know for a fact this is a hardware RAID card. It also has a nifty little battery backup so it can finish writes in the event of a power failure. Since that battery can't possibly power the connected drives, I'm guessing that it just writes the data to on-board flash memory or something and completes the writes the next time the device is powered on. Regardless, it's a nice piece of equipment.

Now of course the OS install disk we're using is informing us that we don't have a valid CD drive attached. Keep in mind that this is coming from a program loaded off a CD. A problem for tomorrow.

On May 9th, I'm leaving the IS department at Rackspace. I like doing dev work on my own, but there is not the place to do it for me. I'm a single Ruby coder surrounded by Python guys and the end result is that I just have nothing to do. I'm looking for something internally, so we'll see how that goes.

Neon : Take Two

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It seems that 64-bit Heron has some trouble recognizing RAID arrays. The machine booted and the RAID controller's configuration screen came up. After tweaking the necessary settings, we bounced the box and prayed that Heron would see it - which it didn't.

When we got to the installation section where we were going to do the partitioning, we were given prompted to choose between the twin 250GB Western Digital drives. Thinking that perhaps, somehow, someway the installed OS would see it we continued through the installation only to hit repeated checksum verification errors during the base system install.

Desperately hoping that this was a fluke, we shut off the machine, coated ourselves in honey, and sacrificed our entire apartment complex to the gods of data integrity and MD5 hashing. No luck (which means the install disk was probably corrupt - I'm having a chat with my LightScribe drive once I finish here). Once the honey had been removed and the police had left, we decided that we'd give Fedora a shot instead - the RAID controller specifically says that it plays nicely with it.

So that's where we stand now - even though Fedora 9 is coming out in about two weeks, we can't wait that long. If there are any hardware issues, we have less than two weeks to find them and get the equipment returned. At least for the time being, a Fedora machine is being added to the rack. I used Fedora at the last place I worked and while I didn't have anything specific against it, I didn't feel particularly attached to it.

As long as we're at it, we might as well trade bash in for tcsh - it's about time I learned some C and from what I understand The C SHell is a good place to learn as a lot of the syntax is similar. I don't have any first had experience though so we'll see.

Switching gears, I've found that a good way to gain some basic day-to-day experience with a language is to use it for any shell scripting needs I have. Erlang being my most recent language of study, that's what I'm going to do. If you'd like to give it a shot, Erlang programs can be run outside of the erl VM by typing:


pratzsch@carbon:/home/pratzsch/shell$erl -compile timely_message.erl
pratzsch@carbon:/home/pratzsch/shell$erl -noshell -s timely_message message -s init stop
Excuse me, your forehead's on fire
pratzsch@carbon:/home/pratzsch/shell$

...while it works, I'll probably end up aliasing that set of commands minus the program name to a bash script (oh, the irony) so I don't have to type that novella every time I want to run an Erlang program from the command line.

Welcome to neon!

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neon_inside_labeled.jpg

These are the insides of 'neon', (not quite fully assembled) the latest web server. This is the first machine I've ever had that has hardware RAID. The chip is an 3.0GHz Intel Core 2 Duo of the 45nm variety, also a first.

The motherboard supports both DDR2 and DDR3 RAM, but it was decided that we'd rather have 4GB of DDR2 than 2GB of DDR3. Naturally, having 4GB mandates a 64-bit OS. We figured we'd give Heron a shot and see how that goes.

man page humor

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Taken from the man page for syslogd (yes, another wild Saturday night):


There are a number of methods of protecting a machine:

1. Implement kernel firewalling to limit which hosts or networks have access to the 514/UDP socket.

2. Logging can be directed to an isolated or non-root filesystem which, if filled, will not impair the machine.

3. The ext2 filesystem can be used which can be configured to limit a certain percentage of a filesystem to usage by root only. NOTE that
this will require syslogd to be run as a non-root process. ALSO NOTE that this will prevent usage of remote logging since syslogd will be
unable to bind to the 514/UDP socket.

4. Disabling inet domain sockets will limit risk to the local machine.

5. Use step 4 and if the problem persists and is not secondary to a rogue program/daemon, get a 3.5 ft (approx. 1 meter) length of sucker rod*
and have a chat with the user in question.

Sucker rod def. -- 3/4, 7/8 or 1in. hardened steel rod, male threaded on each end. Primary use in the oil industry in Western North Dakota
and other locations to pump 'suck' oil from oil wells. Secondary uses are for the construction of cattle feed lots and for dealing with
the occasional recalcitrant or belligerent individual.

Ruby Vector extensions, DNS

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Finally got all the zones configured properly and transferred to my DNS server. In celebration, here are some additions to the Vector class. Enjoy.


require 'matrix'

class Vector
 
  def include?(search_term)
    self.to_a.include?(search_term)
  end
   
  def to_float
    new_elements = []
    self.to_a.each do |element|
        element = element.to_f if element.class == Fixnum
        new_elements << element
      end
          
      Vector.elements(new_elements)
  end

  def pretty  
    counter = 0 
    self.map do |element|
      puts "[#{counter}] = #{element}"
      counter += 1
    end
  end

  def empty?
    return true if self.nil?  
    empty = true
    self.map do |element|
      if case(element)
           when Fixnum
             element == 0
           when nil
             true
           when String
             element.empty? or element == ' '
           when Float
             element == 0.0
           end
        next
      else
        empty = false
        break
      end
    end

    empty
  end

  def self.random(size, max_value = 50)
    elements = []
    (1..size).each do |i|
      elements << rand(max_value) + 1
    end

    Vector.elements(elements)
  end

end

Taken from http://whois.domaintools.com/wordpress.com


Server Type: nginx/0.6.29

So it appears that Wordpress, which gets about 4 million hits a day has switched to an Nginx front-end! I really wish that tomorrow someone at work would say that no high-traffic sites uses Nginx. Of course I'd settle for an ignorant quip about how no there are no enterprise-level uses for Ruby or Rails.

It appears that the project I was on at work which was killed has risen from the proverbial ashes and is once again active.

I've been having DNS troubles since yesterday. First the serials weren't getting updated, then a full zone transfer wouldn't complete without an error, and now I've FINALLY eliminated all the errors in the DNS side of things. Not that it's working, of course. Now the trouble is that the external IPs of two of my boxes have been switched. So while it's resolving the domain names to the correct IP, that IP is tied to the wrong box. I should have it fixed by morning.

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This page is a archive of entries in the Network category from April 2008.

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