Friday, 17 February 2012

Add SSH public keys to a remote host

Nice quick way to add public keys to the authorized_keys file on a remote host
ssh-copy-id -i ~/.ssh/ user@hostname

Monday, 13 February 2012

Rocks Cluster Compute nodes Ask for Password

After installing the compute nodes on a new Rocks Cluster it was found that a few nodes kept asking for SSH password. These should have been passwordless SSH and it was working on some of the compute nodes.

Try the following #rocks sync host sharedkey compute 

Try #rocks run host "/opt/rocks/bin/411get --all" 

if that works, 

Try #rocks sync users on the frontend

This cured the password prompt problem on the cluster.

Monday, 6 February 2012

4 Litre Silver Mini Fridge Repair

After just over a year of use (just out of warranty) the fridge stopped keeping things cool.
After taking out the 7 screws from the back panel the power supply PCB was revealed. On close examination it was found that the two 1000uF 25Volt electrolytic Capacitors on the power supply board were swollen (see picture below and note the pressure seals on the capacitors, both are leaking electrolyte), they were replaced and the fridge began to cool again, Result!
Do these repairs at your own risk, electricity is dangerous, you have been warned.

CNC 6040 Spindle Control

Note: This is only an on - off control there is no speed control due to limitations on the CNC control box , you set the speed using the pot...