Difference between unmount and eject ....

Question

Difference between unmount and eject ....

HI,

I have a USB external hard disk with 2 partitions for my daily backup. I just realized from the Apple's DiskUtility that when I eject/unmount my partitions from the Finder, that the hard disk itself is not ejected. If I want to fully eject it I can do it from ADU.

Is there a problem to unplug a USB drive when the partitions are unmounted but if it is not fully ejected ?

Is there a way for fully ejecting the external drive from the Finder ?

Thanks in advance.

Robert

Happy owner of an iMac G5 !!!!, Mac OS X (10.4.8), 1.6 GHZ - 17" - 2.0 Go

Posted on Feb 17, 2007 5:08 AM

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Answer 1

Feb 17, 2007 11:35 AM in response to Robert Lesperance

Hi Robert

The difference between unmounted and ejected is as follows:
unmount removes the volume. You can have multiple partitions on a volume, and only unmount one of them for example. This would leave the unmounted volume available to be mounted again.

eject removes the drive, and in the case of firewire and usb spins down the drive. This will also unmount all volumes on that drive. Once a drive has been ejected it has to be un-plugged and re-plugged to the machine to enable the volume to mount again, akin to ejecting a cd and then putting it back in the machine.

If you just unmount a volume, the drive can still be connected and spun up, in which case it is not necessarily safe to unplug it!

I hope that clarifies things?

Regards

David

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Answer 2

a brody

Level 10

85,296 points

Feb 17, 2007 5:18 AM in response to Robert Lesperance

Unmounting and Ejecting are the same.

If you still see the icon of the drive on the desktop after unmounting it, then it is just a matter of the slowness of USB, and you have it be patient for it to disappear.

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Answer 3

a brody

Level 10

85,296 points

Feb 19, 2007 6:48 AM in response to Robert Lesperance

You can remove a drive, so long as all of the volumes have been dismounted or ejected. If you only eject or dismount one of two or more volumes, you can't remove the drive. Your only indication that the volumes have been dismounted will be in the Finder Sidebar of a Finder window or desktop, depending on which one you have set to show removable volumes.

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Answer 4

Feb 17, 2007 5:58 AM in response to a brody

Hi abrody,

When I click on the black triangle at the right of the partitions's name in the Finder window, the partitions unmounts. But by looking in Apple's Disk Utility it seems that the drive is still not fully ejected.

Try it. After unmounting your partitions, go in ADU and you will see that the main drive's name is still black and that the EJECT choice is still available fir the main drive. After clicking EJECT the drive fully ejects and it's name dissapear from the left panel in the ADU.

I don't think that the speed of the USB connection is the issue. In the DU both choices are available and named differently. To what I understand and experience, there must be a difference between UNMOUNT and EJECT.

These are the reason for my question: What is the difference between these 2 states ? Relating to mu USB drive, can I safely power down and unplug my drive even if the main drive's name is not ejected in the ADU left panel ??

Thanks for your help.

Robert

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Answer 5

a brody

Level 10

85,296 points

Feb 17, 2007 6:22 AM in response to Robert Lesperance

Disk Utility shows available partitions mounted and unmounted. As long as the disk does not appear on the desktop, if it had appeared on the desktop before, then you can safely assume it is unmounted and ejected.

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Answer 6

Feb 17, 2007 6:32 AM in response to a brody

I do not show mounted disk/partitions on my desktop. I only allow them to show up in the Finder window.

I suppose that your comment applies to both equally and that if the partition does not show up in the Finder window that I can safely power down and unplug my hard drive.

Thanks.

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Answer 7

a brody

Level 10

85,296 points

Feb 17, 2007 6:44 AM in response to Robert Lesperance

Yes.

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Answer 8

Feb 19, 2007 6:47 AM in response to David White17

So who is right ?? Is it or not acceptable to unplug a disk if the main hard disk has not been fully ejected ..?

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