Shutdown Scripts for Linux and Windows

Before We Get Started.

Yes I know Powershell is an awesome tool so please don’t take this post as the only way to accomplish this task. Since I work in large enterprise networks that run pre-08 Windows boxes it’s not always possible to install Powershell just to execute my scripts. I focus on the task to be done not how to make my life easier.

Problem Statement:

In my home office I have a very powerful little box setup with VMWare ESXi that hosts several Windows and Linux guests. When these guests are all running (around 15 or so) the CPU fan kicks into high gear. During the day this is not a problem but at night the whining from the fan is just annoying. So each night I have to log into each guest and shut it down manually. I was in need of a way to shutdown these virtual boxes remotely without logging into each one. Continue reading

NewSQL vs NewSQL (oh and noSQL)

Yes the title is correct. Currently in the technical arena you have two similar technologies referring to themselves by the name NewSQL. I was reading a post about how Facebook has backed itself into a corner with its complex deployment of MySQL and how NewSQL or noSQL could be their solution. This was the first time I heard about NewSQL so I decided to do some research and what I found was very interesting but confusing at first. Continue reading

Delayed ACK

A few weeks ago, during a technical group meeting I hold here in town, a question came up that is now the basis of our next meeting. Does every TCP segment get an ACK returned?

My unqualified answer to this question was “No” as I had troubleshot some connections before and noticed that not every TCP segment received was sent an ACK. When challenged on this I couldn’t give the technical background for this just that this was my experience. Of course others in the group had different experiences so the only way to solve this was to do the research. Continue reading

RFID Thoughts

Several years ago I attended an RFID conference in Las Vegas. It was the first time that I had been to one and was very excited to see how RFID was being deployed and how Walmart’s push for RFID several years earlier had impacted the implementation of this technology. During this two day conference several early adopters presented and explained how challenging a simple technology can be to implement. It was well understood by the early adopters that this was a growing technology and the challenges they faced today would soon be overcome. The 90% read rate of the tags as one presenter stated was due to quality control of the tags and some times it was a result of antenna placement. Even with all the challenges and incorrect cost estimates the benefits were obvious. They felt confident that the tags quality would increase and that with education the antenna placement problem could easily be overcome. Other problems such as the environmental impacts on RFID where the basic physics of how radio frequencies are retrieved from a tag would be a greater problem and much more skepticism was around that it was a solvable problem. Continue reading

Google Wallet.. Has NFC arrived and will Apple be too late?

Last week Google announced their mobile payment system that utilizes Near Field Communication (NFC). This is just one more functionality that Google is adding to the list of uses for NFC. To be honest this was the main driving force behind the development of NFC to begin with. NFC is a type of RFID that operates at a specified frequency (13.56Mhz) and offers two way communications. It has a very limited range which is why it is ideal for payment processing. Continue reading