Hard drive protection
Posted Oct 14, 2005 17:08 UTC (Fri) by giraffedata
Parent article: Hard drive protection
This function is totally out of place in the block layer. The matter of an impact destroying a device has nothing to do conceptually with storing and retrieving blocks. It is conceptually possible not only for a block device to involve no impact-sensitive hardware, but for impact-sensitive hardware to involve no block device.
This needs to go well below the request queue, down nearer the level where things like physical shock are understood.
It seems to me that a device driver that can use warning of an impending shock to protect its device should just register with a totally independent service to be notified. Assuming it's a disk device implementing a Linux block device, then when the driver gets notified, it parks the heads and delays sending any new requests to the device for a while; to the block layer, it just looks like a long-running request.
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