Wednesday, 21 October 2009

Predicting Mechanical Failure in Hard Disks

There's many kinds of failure in Hard Disk Drives, but I want to simplify the discussion here. So let us define two basic types of failure.

Type 1: Software Failure: A relatively simple problem, will not be covered on this blog.

Type 2: Mechanical Failure: When the motor or bearings or the read/write head of the Hard Disk fail.


Image Ctsy. LapTopRecovery.Net


We will cover only Type 2 failure here.

Every drive has an inbuilt mechanism. Known as "S.M.A.R.T."

This mechanism is an 'early warning mechanism' that informs you of the mechanical health of your drive. And can inform you if your drive is about to fail, mechanically.

There's many S.M.A.R.T monitoring programs available. But not all function correctly for some reason.

I found that the following programs informed about drive health successfully. I used them on healthy as well as failing drives at my office.

1. HDD Sentinel.

2. Drive Health ™.

Interpreting S.M.A.R.T can be difficult at times. I found HDSENTINEL to be easiest to understand as far this is concerned. It explains each parameter in simple terms. It also has the ability to monitor S.M.A.R.T. on external drives, which other softwares don't.

Both these softwares will also show you your Hard Drive Temperature.

It is vital to keep the hard disk cool and free from dust and moisture.

Please refer to your Hard Disk Manual for the acceptable temperature/humidity range for your hard disk.
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If you want to monitor your Hard Disk health more effectively, then monitoring the voltages that are being fed to your PC internals is not a bad idea. A software for doing this is:

1. SpeedFan.

This software can monitor many internal parameters. But it is NOT recommended to be used to monitor S.M.A.R.T. Though it has the ability. I found its S.M.A.R.T. monitoring to be vague and therefore useless.
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Sunday, 18 October 2009

Lets Get Electrical - 2

Some more examples of how Electrical Noise can be dealt with.

There is no 'one perfect solution for all'.
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In Diagram 2, the delicate electronic devices circuit is completely cushioned from its surroundings via an Isolation Transformer.




In Diagram 3, the Online UPS has also been isolated from the surroundings.