Use Memtest86 Before Deploying Servers

January 27th, 2010 admin Posted in Hardware, System Admin 1 Comment »

We’ve been building a few servers recently, and as part of our testing we performed a memory test on each of the machines. In doing so we discovered that one of the RAM modules was defective. We confirmed that the memory, not the cpu nor motherboard, was at fault by then testing the RAM in another machine.

System memory can be defective without being overly apparent, allowing you to install your operating system and use it normally for a period of time. After a while programs may begin to crash unexpectedly, and other system errors may occur.

By running Memtest86 before shipping the servers to the datacenter we have saved ourselves countless hours of remotely debugging the issue and coordinating a replacement of the hardware.

Memtest86 is free and can be downloaded as a bootable iso and in many other formats here. It is also bundled on Ubunutu installation disks, just boot from the cd/dvd and run the “memory test” option.

Below is a screenshot detailing over 400,000 memory errors. Working memory should not return any errors at all, one single error is cause for concern.

Check out the Memtest86 website for more details on how to determine which memory module is at fault, and whether your bios or voltage settings may be to blame.

Click here to view full size

AddThis Social Bookmark Button

SRF10 With An Arduino Mega

November 20th, 2009 admin Posted in Hardware No Comments »

One of the projects that we are working on requires ultra sonic range finding abilities. We’ve used the SRF10 with an Arduino Mega to do this.

Code: http://dl.dropbox.com/u/491583/weblinked/srf10_demo_incero_dot_com.pde

Hookup:

  • 5v on arduino goes to 5v on SRF10.
  • Resistor goes from 5v on arduino to SCL on SRF10.
  • Resistor goes from 5v on arduino to SDA on SRF10.
  • SCL on arduino goes to SCL on SRF10.
  • SDA on arduino goes to SDA on SRF10.
  • GND on arduino goes to GND on SRF10.

Video:

Hookup Photo:
Click here to view full size

AddThis Social Bookmark Button