Spin down HDD after disk sync or before power off
dthiele at gmx.net
Thu Mar 5 13:22:01 PST 2009
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Alexander Motin wrote:
| Daniel Thiele wrote:
|> Oliver Fromme wrote:
|> | Octavian Covalschi wrote:
|> | > I'm looking a way to spin down HDD just right before power off. Why?
|> | >
|> | > Because currently when I call "shutdown -p now", HDD is powered off
|> at it's
|> | > full speed (7200.4) and as a result
|> | > I hear a noise of stopping/spinning down of HDD, and _this_
|> concerns me as
|> | > I'm afraid it can damage HDD.
| I am not sure that there is any problem. Last 10 years drives using
| electromagnetic head positioning which mechanically parts heads on power
|> | [...]
|> | You can't do anything from
|> | userland at this point. If you want to insert a spin-down
|> | for your disks, you will have to modify the kernel.
|> That is what I did and am still doing successfully since 2006.
|> for my initial problem description and
|> for the "solution". Note that back then David Tolpin
|> (dvd at davidashen.net) suggested to use
|> " ... & (ATA_SUPPORT_APM|ATA_SUPPORT_STANDBY)"
|> I don't know if that is the way it should be done, but for me it worked
|> across 3 hard disks and two notebooks so far. I am aware that 3 disks
|> and 2 notebooks provide very limited test results, but maybe this work
|> around solves your problem, too.
|> It would still be great, though, if a proper solution for this could be
|> permanently implemented into FreeBSD. That is, if the current behaviour
|> really is not that healthy to hard drives, as Joerg suggested.
| I have thought about doing that on device detach to prepare drive to
| mechanical shocks in case of drive physical removing. But to work
| properly it requires some changes in ATA core to be made first to
| protect against submitting commands to already physically removed drive..
| I can agree with doing that on suspend if ACPI does not doing it
| But on system shutdown having meaning of reboot, I think, commanding
| drive IDLE will just lead to additional mechanical and power stress for
| drive and PSU when drives will be spin-up in just a few seconds after
On reboot I do not observe the drives "click" noise, but the drive, too,
gets powered off (without any patches). So I think that the ad-hoc fix I
mentioned above does not introduce any additional stress to the drive on
reboot or am I missing something?
Looking at the numbers in the Hitachi drive specifications Tobias an I
dug out from the Hitachi website (see replies in the Joerg Sonnenberger
branch of this thread) the normal Load/Unload count is about 30 times
higher than the Emergency Unload count. So even if an
ATA_STANDBY_IMMEDIATE command may introduce additional Load/Unload
stress on reboot it is not as bad as the stress causes by an Emergency
Unload on shutdown. Of course this only applies if the "click" sound is
really caused by an Emergency Unload. Is there a way to figure out?
Maybe the S.M.A.R.T. feature records the two kinds of power-offs.
Additionally, the Hitachi TravleStar 5K320 specification states that it
is the host systems job to execute the drives proper power-off sequence.
The TravelStar 5K100 specification, on the other hand, mentiones that
the BIOS is responsible for that.
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