Noel's Muses

For decades most Data Centre's utilised raised floors to inject cool air from underneath up to the racks in a back to back arrangement, this is called the Hot aisle Cold aisle method, but for some years now this method is considered outdated and rather inefficient for Data Centre cooling.



This method, as seen at left, involves hot air from hardware released from the rear door of a rack into the general Data Centre airspace, to assist with some form of hot air containment, most rows of racks will be so two rows are back to back, but, this still allows for hot air mixing with cold air as they are not truly contained for exhaust.

Many modern Data Centre builders have got it right in what makes far more sense using the all Cold aisle method, which involves an overhead plenum for the hot air to be expelled into, this means only cold air in your DC, and no mixing of cold and hot air, since the idea is to keep everything cool so your valuable hardware stays at a safe operating temperate.
Continue reading "Data Centre Cooling"

In this day and age, I think it is wise that people use digital signatures with methods such as GPG/PGP to prove authenticity and using its encryption capabilities for privacy when storing mail on untrusted networks, such as those hosting mail in other countries, especially those countries who have questionable laws regardng privacy.

GNU Privacy Guard (GPG) is a free-software drop-in replacement for Symantec's proprietory PGP cryptographic software suite.

It is useful in many ways, from saying "Yes, I really sent that message", to using it to encrypt a message or files for privacy, to something as important as signing a checksum file, after all, what's the point of creating a checksum for a file, since if your machine is compromised, all they need to do is to recreate a new checksum and you're none the wiser, but this is harder to get around when it is also expected to be digitally signed by someone.

Continue reading "Digital Signatures and Encryption with GPG/PGP"