[kenny1999]

Hello

Concerning external hard disk, especially the 3.5 inch one, I have some "if"

(1) if I don't do safely remove and unplug the USB cable,

(2) if the computer suddenly goes off and the hard disk is still actively connected to the computer (my computer could go off because of temporarily power outrage of the old building I am living or other reasons)

(3) if the hard disk is moved very slightly (usually accidentally) during its working,

(4) for any other reasons the hard disk is still vibrating / spinning but the usb cable or power cable is taken away.

would any of the above "if" lead to loss/corruption/alternation of data ALREADY FINISHED AND STORED?(I don't mean the data BEING transferred, I know those data has to be re-transferred again). Are the hardware of a harddisk designed to avoid those problems.

Thank you all

[dietrc70]

No, you just need to worry about all the data being written completely. Modern drives are designed not be damaged if they lose power suddenly.

This post has been edited by dietrc70: 07 March 2013 - 05:39 PM

[orion24]

1 - No problem if the HDD has finished it's job (that is usually 1-2 seconds after the OS reports the file transfer is finished)
2 - Again if the HDD is not writing or modifying anything there is no loss (except the one in the main RAM)
3 - No problem at all. But the less it moves, the better.
4 - Same as 1 and 2

Both hardware and software are designed not to avoid, but to limit problems like those. Eg the OS usually prefers to disable the HDD write back cache by default (less performance) just in order to limit the data loss probability in case of a power failure. Personally I loved it the way it was with AT and MS-DOS. You just pressed the off button and it was turning off without ifs and buts. And it was your responsibility to make sure floppies and HDDs had finished their job. But it was too easy at the time. You always knew what was running in your PC and when. Right now there are so many background staff silently going on that it drives me nuts.

BTW, using an external HDD, the main thing I'd be worried about is overheating. Not only does it have no fan, but it is inside a tight case as well.

[sub.mesa]

Configure your external harddrive to 'optimize for quick removal' instead of 'optimize for performance'. This will disable write-back on your external harddrive and this will increase the chance no corruption to filesystem metadata occurs in case of crash/disconnect/power failure.