Spin down HDD after disk sync or before power off

[Alexander Best]

imo this patch takes good care of the problem. would be nice to have it in
HEAD.

cheers.
alex

Warren Block schrieb am 2010-01-30:
> On Fri, 29 Jan 2010, Jung-uk Kim wrote:
> >On Friday 29 January 2010 05:38 pm, Warren Block wrote:

> >I am not 100% sure but I think it should be something like the
> >attached patch.

> Yes, I had the two commands backwards.  So let me try to summarize:

> ad_shutdown uses ATA_FLUSHCACHE writes out any cached data, but does
> not park the heads.  At powerdown, the heads do an emergency park,
> which is louder than a normal park and possibly damaging.

> Adding ATA_STANDBY_IMMEDIATE after the ATA_FLUSHCACHE will park the
> heads more quietly and possibly more safely.  Should do no harm, at
> least.

> ad_spindown looks like it's meant to spin the disk down for sleep
> operations, and does some higher-level things.

> I suspect flushcache and standby should be as close together as
> possible to avoid the chance of anything getting back into the cache
> or spinning the disk back up.

> Anyway, testing this use of ad_spindown inside ad_shutdown brought
> back the GLINK on shutdown.

> A fixed version of the earlier patch that does flushcache and then
> standbyimmediate is attached.

> -Warren Block * Rapid City, South Dakota USA