Turning off external HDDs?

I have one connected to a USB3 & a wall socket.
https://www.overclockers.co.uk/media...39_800x800.png

It works fine, but is there any way to have it turn off when the
computer is shut off?

Is there some off-the-shelf gadget to connect it to the computer power
supply?

On Wed, 13 Dec 2017 07:57:07 +1100, Peter Jason wrote:

I have one connected to a USB3 & a wall socket.
https://www.overclockers.co.uk/media...39_800x800.png

It works fine, but is there any way to have it turn off when the
computer is shut off?

Is there some off-the-shelf gadget to connect it to the computer power
supply?

You can get a power board that will turn of other device plugged
into it when the main device is turned off.

Peter Jason wrote:
I have one connected to a USB3 & a wall socket.
https://www.overclockers.co.uk/media...39_800x800.png

It works fine, but is there any way to have it turn off when the
computer is shut off?

Is there some off-the-shelf gadget to connect it to the computer power
supply?

I have cheap enclosures that spin down when the PC drops power to
the USB port. You see the LED go out, just before the PC goes off.
And listening to the drive, it's no longer spinning.

Even if I use "Safely Remove", the LED goes out and the drive
stops spinning. Then, it's really safe to use the power switch
on the drive and remove +12V/+5V. And later unplug it.

I could find one question on the Icy Box forum, where someone asks
whether the feature could be added to your product. Implying it
remains spinning. I have some older enclosures that did
stuff like that.

Generally, it's not good to remove power while the disk is
spinning. The disk will use its emergency power removal routine.
The spindle becomes a generator, and generates enough power for
the write cache to be dumped to disk. Some relatively recent
6TB or larger drives, now use Flash memory for emergencies, and
they store the 256MB disk internal cache RAM chip, in some
Flash memory on the drive. Which reduces the risks involved
with the emergency power fail routine (on the large drives, it
takes too long).

If it was me, I would first change enclosures, to get the
proper spindown behavior. Then I'd go looking for the kind
of device the poster "Lucifer" is suggesting (if I wanted to
avoid the tiny amount of power wasted keeping the wall adapter
running).

Hard drives log the number of times they've been forced to endure
a power failure. So that's a S.M.A.R.T parameter you can look
at, to see how many times you've caught the drive unaware of
what is about to happen.

As long as the OS sends a flush command, drops the link power
state to the enclosure, this gives the enclosure firmware
a chance to spin down the drive. Once in the spun down state,
the drive no longer has any opportunity at all to do any
"emergency" stuff, because now, there's no kinetic energy to
harvest and use. Even the drives with Flash memory wouldn't
be able to respond. And when the drive spins down in that
case, all its toys should have been put away, so it's in
a safe state.

Drives can also spin down or park the heads in mid-session.
While the platter might still be spinning (a source of
kinetic energy), it's not clear to me whether that
state is quite as safe. The OS in that case, thinks the
drive is still there, and if the OS "probes" it, it wakes
up again after about 5 seconds. Which means there might even
be outstanding writes to be done.

Is picking enclosures easy ? Is this behavior documented ? No.
When I bought mine, I had no idea what would happen. It just
happened to work out.

My newest hardware purchase, doesn't even have a LED, so I
can't tell what state it's in.

Paul

Peter Jason schreef op 12-12-2017
in :
I have one connected to a USB3 & a wall socket.
https://www.overclockers.co.uk/media...39_800x800.png

It works fine, but is there any way to have it turn off when the
computer is shut off?

Is there some off-the-shelf gadget to connect it to the computer
power supply?

usb master slave power switch

--
MdW.

On 12-12-2017 21:57, Peter Jason wrote:
I have one connected to a USB3 & a wall socket.
https://www.overclockers.co.uk/media...39_800x800.png

It works fine, but is there any way to have it turn off when the
computer is shut off?

Is there some off-the-shelf gadget to connect it to the computer power
supply?

buy a power block, controlled by the on/off of the computer.

On 12-12-2017 21:57, Peter Jason wrote:
I have one connected to a USB3 & a wall socket.
https://www.overclockers.co.uk/media...39_800x800.png

It works fine, but is there any way to have it turn off when the
computer is shut off?

Is there some off-the-shelf gadget to connect it to the computer power
supply?

Google for "master slave socket"

The computer in the master socket, switches the other
sockets when going off/on, including your usb disk.