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Temporarily Parking the Hard Disk Heads

Hi,

I've an embedded Linux booting from a flash disk and running on a PC104+ stack.

This PC104+ computer is carried on a moving platform and occationallyy subject to high vibration. I do have know when vibrarion will start and the duration of the vibration.

Some time I do attach an IDE hard disk (40-160GB) to my embedded Linux system for high speed high volume data logging. Due to the occational vibration, I would like to be able to park the hard disk heads just before the vibration starts and re-activate logging when vibration ends.

I wonder if there is a way of temporarily moving the harddisk heads to parking position and back?

Thanks,

Miem Chan miemchanATyahooDOTcomDOTau

Reply to
Miem
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Hello,

Using a spinning hard disk, this is bad, even if put to sleep.

I don't believe modern disks have a special "parking position" but you could stop them spinning.

You can put the disk directly into standby or suspend mode using "hdparm -y" respective "hdparm -Y". hdparm is included with busybox, with the needed parameter, if I remember correctly.

Another idea would be to set the spindown timer very low (hdparm -S), so that the disk spins down after maybe 5 seconds of inactivity. But you have to ensure that no further accesses occur. Then you only have to stop activity on the disk before vibrations occur. But it won't be good for your disk as it shouldn't vibrate while spinning...

Hope this helps,

Sebastian

Reply to
Sebastian

I believe they still have a parking position, but you don't have to manually position them. They snap the heads to a safe location using internal stored power when power is removed.

Reply to
AZ Nomad

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