[OT] drive behavior on power-off (was: Disk write cache)

Matthias Andree
2005-05-16T16:01:02Z

On Mon, 16 May 2005, Richard B. Johnson wrote:

> Then I suggest you never use such a drive. Anything that does this,
> will end up replacing a good track with garbage. Unless a disk drive
> has a built-in power source such as super-capacitors or batteries, what
> happens during a power-failure is that all electronics stops and
> the discs start coasting. Eventually the heads will crash onto
> the platter. Older discs had a magnetically released latch which would
> send the heads to an inside landing zone. Nobody bothers anymore.

IBM/Hitachi hard disk drives still use a "load/unload ramp" that
entirely moves the heads off the platters - I've known this since the
DJNA, and it is still advertised in Deskstar 7K500 and Ultrastar 15K147
to name just two examples.

--
Matthias Andree