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Monday, June 30, 2008

Why monitor humidity in computer rooms?

Temperature sensors are our number one selling sensors. No doubt about that.

Last week we tried to explain the difference between ambient temperature monitoring and monitoring the temperature inside a rack, where your systems operate.

The fact that one is doing temperature monitoring is a big leap forward. Temperature is the threat we are most familiar with: entering a boiling server room when the airco unit went down - a familiar sight for many people.

A less visible threat to your equipment is humidity. Less visible also means more neglected; people omit to consider the danger of humidity related to their equipment.

There are 2 threats posed by humidity:
- ESD or Electrostatic buildup and discharge
- Corrosion

Everyone is familiar with corrosion: let metal stay in the rain and you will see it appears. With high humidity levels slowly your components could start showing signs of corrosion resulting in permanent loss of systems and potentially data too.

A low humidity level is a big contributor to the risks of ESD in a computer room, server room or data centre. Industry experts have determined that the risk of ESD increases the lower humidity is and the cooler the room is. Finding the right balance is tricky.

What are the recommended humidity ranges? Most strict ranges advocate humidity between 40% and 60%

Higher than 60% and corrosion may appear. Lower than 40%, ESD is your main ennemy.

Tuesday, June 17, 2008

Temperature monitoring in a server room

A question we often get from customers is: "how many sensors do I need?"

The actual question a customer needs to ask himself is: "how much do I want to spend on environmental monitoring?"

The basic monitoring is temperature. In later posts we will explain the benefits of other types of monitoring.

There are 2 main types of temperature monitoring:
- ambient temperature monitoring
- rack temperature monitoring

Ambient temperature monitoring is capturing the temperature in the room the same way you feel it when you are standing it. It is the temperature reading used by air conditioning units to operate.

However it is not the temperature in which your systems operate. In a number of server rooms we visited each time we could sense so called "hot zones". These are area's in the room where it is much hotter compared to others; often due to either layout of the room (cornered) or type of equipment (ie heavy server concentration in one area).

The problem with ambient temperature is that it takes some time to increase above a treshold when an issue arises in one particular area. If you are sitting in front of a fire place, it will be way warmer than in the rest of the room; especially when the room is larger. Same applies here.

In order to detect issues faster, one solution is to put every 3-5 meter or 10-15 ft a temperature sensor.

Best practice however is to monitor each rack individually with one sensor per rack. Using our IP based sensors, the sensors are positioned at the rear of the rack and near the top. Remember your physics class in high-school: hot air climbs.

The more sensors you deploy the earlier you will detect an issue.

However just one sensor in a room is far better than doing nothing.

Monday, June 2, 2008

Voice alerts & SkypeOut - an industry first

ServersCheck was one of the first server monitoring software providers to provide a full web enabled platform back in 2003 when we started.

As our competitors, we all had nice email alerting features and some like us even had integration with Instant Messengers. In our case this was intially ICQ and then we moved to MSN.

We all overlooked one key issue: what if the network is down? If there is no Internet connectivity, then emails don't get to Blackberry's, instant messages can't be sent. People would not be notified of an issue.

We had to find another way of notifying people and we turned to Text to speech technology. By using a voice capable modem, people can receive notifications through a telephone call. This feature was introduced back in 2004.

As we are not always available to pick up phone call, calls and subsequent alert messges could be missed. To overcome this we integrated the support for SMS messages through GSM modems as an alert option. As SMS messages are almost always received, it is still today one of the most reliable ways of sending out alerts (in conjunction with the other alert options).

With SMS introduced, we decided to discontinue telephone call as an alert option since SMS was so much more robust.

What we didn't realize was that in quite a number of situations, SMS is not an option:
- server room in a cellar with no wireless network
- security guard that needs to be notified
and so many more

With that valuable feedback received from many customers, we decided to reinvest into the telephone call alerting option and make it better as it was before.

It is now powered by a semi automated attendant that allows us to make sure that a call is received and that the alert message is played at the right time. You can now define the number of times the software should retry and with which interval.

We even went one step further and brought a new innovation in the monitoring software industry: alerts via Skype.

ServersCheck can now use Skype's SkypeOut feature to call land line phones without the need of a modem attached to the system running our software. Of course keep in mind that when the network is down, Skype will be unavailable too...

Sunday, June 1, 2008


Welcome to the new ServersCheck blog.

The purpose of this blog is to share with our users experiences, best practices, tips and tricks regarding our products.

New blog articles will be posted on a weekly basis.