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by Ray DeCosta

Q. I'm in the habit of just removing my USB flash drive from my computer when I'm done with it. A friend said that this is wrong and I risk losing all my data. What is he talking about?

A. When data is written to a device such as a hard drive or a flash drive, it is first put into a buffer and then written to the device. For performance reasons, the data is not always written from the buffer until it is full. This leaves the possibility that removing the device before the buffer is emptied of its data will cause you to lose it. This could cause the entire file to be corrupted and, in the very worst-case scenario, you might lose ALL data on the device.

Your computer handles hard drives differently than the common USB flash drives. These drives are generally set to "Optimize for performance" which means they don't normally write from the buffer until it is full or the computer is shut down.

Flash drives are usually set to "Optimize for quick removal". In this case, the data is written immediately to the drive and you may safely remove it whenever you want to. However, unless you confirm that each flash drive is indeed set properly, you do risk the loss of data by simply removing the drive. It's a good habit to always use the Safe Removal icon in the lower-right corner of your Desktop to remove any external device from your computer.

Published: Courier 4/4/10 - Page 5C