Re: [gentoo-user] External hard drive and idle activity

[Grant Taylor]

On 1/1/20 5:09 PM, Dale wrote:
> Howdy,

Hi,

> As some may recall, I have a 8TB external SATA hard drive that I do
> back ups on.  Usually, I back up once a day, more often if needed.
> Usually I turn the power on, mount it, do the back ups, unmount and
> turn the power back off.  Usually it is powered up for 5 minutes or so.
> When I unmount it tho, I sometimes notice it is still doing something.
> I can feel the mechanism for the heads moving.  It has a slight
> vibration to it.  Questions are, what is it doing and should I let it
> finish before powering it off?  I'd assume that once it in unmounted,
> the copy process is done so the files are safe.  I guess it is doing
> some sort of internal checks or something but I'm not sure.

There might be some activity for up to 30 seconds after umount finishes 
and returns to the command prompt.

Note:  umount will normally block until buffers are flushed to disk.

> Is it safe to turn it off even tho it is doing whatever it is doing?

I wouldn't.

> Should I wait?

I would.

> Does it matter?

Maybe.

Is the drive SATA connected or USB connected to the machine?

In some ways it doesn't matter.  You can tell the kernel to eject the 
drive.  Once that finishes, there is no active remnants of the drive in 
kernel.  5–15 seconds after that and you should be quite safe to power 
the drive off.

echo 1 > /sys/class/block/$DEVICENAME/device/delete

That will cause the kernel to gracefully disconnect the drive.

> Thanks.

:-)



-- 
Grant. . . .
unix || die





-- 
Grant. . . .
unix || die