Help!

MacNewbie80

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Hi all,
I bought a mac a few months ago and still confused when it comes to dealing with external hard disks with mac. I have a WD hard disk which worked perfectly with my mac but then started to give me errors whenever I tried to write something on it. I reformatted it but still have a problem: can't write on it, and tried to repair/erase it from disk utilities but always get the same message: failed to unmount disk.
I also tried the partition option but still get the same message. Please help :(
 
Hi MacNewbie80. For future reference, please give a more informative title to your thread. Possibly something like "Problem with External Disk on my Mac" that would tip people off that are browsing the forums. We already know that you need help, for that's why you're here. :) But a brief but informative thread title does wonders.

As for your drive, when it was working fine, were you disconnecting it by either control-clicking on the mounted drive located on the desktop and selected to eject the drive? It's always best to eject an external USB or Firewire drive before you physically disconnect it because otherwise you can corrupt your drive. When you tell the external drive to eject before disconnecting it, all final writes to the drive are made before you can safely remove it from the port you connected it to. This is the same practice in Windows and all other operating systems.

Might there be some sort of lock on the external drive itself? I know that some do have this ability (at least some USB flash drives do). If the external drive is formatted for the Mac, have you tried repairing permissions on the external drive itself to see helps?
 
Hi nixgeek, no I always ejected the drive before physically disconnecting it. I also forgot to mention that partitioning the disk worked fine yesterday until I tried to write data on it. That was going on fien until it suddenly stopped and gave me an error. Now partitioning doesn't work. I also can't eject it anymore, gives me a message that it's in use and can't be removed.
 
Also, where are you connecting the drive to? Are you connecting it directly to a port on the Mac itself or are you using the ports available on the keyboard? Do you have this drive connected to a USB hub or some sort?
 
Hi all,
I bought a mac a few months ago and still confused when it comes to dealing with external hard disks with mac. I have a WD hard disk which worked perfectly with my mac but then started to give me errors whenever I tried to write something on it. I reformatted it but still have a problem: can't write on it, and tried to repair/erase it from disk utilities but always get the same message: failed to unmount disk.
I also tried the partition option but still get the same message. Please help :(

Try this and see if it helps.

Launch Activity Monitor (in your Utilities folder). See if there is anything running that is on that external hard drive. If so, choose the item that is running, and then click on the stop sign icon that says "Stop Process" at the top of the screen.

Once all processes are killed that are running on the external drive, try running your hard drive repair utilities again. They will probably run normally now.
 
It was worth a shot. Often a drive will refuse to unmount because something on it is running. If the drive won't unmount, most disk repair utilities won't touch it.

You might want to leave Activity Monitor's window open for a while and see if anything pops up.
 
Randy, I'm curious. MacNewbie80 mentioned that the drive was formatted and still gave errors writing files or unmounting. What could possible be on the drive that is in use other than the drive itself?

I'm wondering if it's time to check the drive with something like DiskWarrior.
 
Randy, I'm curious. MacNewbie80 mentioned that the drive was formatted and still gave errors writing files or unmounting. What could possible be on the drive that is in use other than the drive itself?

Good question. I don't know offhand. All that I know is that fairly recently I helped someone having a similar problem where they couldn't unmount their hard drive, and they could only turn off their computer by unplugging it. It turned out that something was running, and when it was killed they could finally shut down. It had something to do with something set to launch on startup, as I recall.

Maybe he should look in:
System Preferences/Accounts/Login
and see if anything stands out.

I'm wondering if it's time to check the drive with something like DiskWarrior.

That would be a good idea, but DiskWarrior requires the disk to be unmountable (is that a word?) to repair it, if I recall correctly.
 
Does DiskWarrior boot on its own? if so, then that might be one way it should be able to check the external drive without the installed OS holding it hostage.
 
Does DiskWarrior boot on its own? if so, then that might be one way it should be able to check the external drive without the installed OS holding it hostage.

Yes, the CD that DW comes on is a boot disk. (Though it takes forever to startup.)

But that should work!

if the problematic external hard drive keeps him from switching startup drives, he can always detach the drive (USB and Firewire are hot plugable), startup from the DW CD, and then plug in the external drive.

I hope that's the solution! Nice thinking, Nixgeek!
 
Ok, people who are forgetting I am a newbie, so what I should do is install DiskWarrior and it would check what's wrong with the hd?
Also Randy, the computer shuts down without removing the hd which shows that it's not running, correct?
 
Ok, people who are forgetting I am a newbie,

Opps! Sorry! We were talking at you, rather than with you.

so what I should do is install DiskWarrior and it would check what's wrong with the hd?

Disk Warrior ($100)
http://www.alsoft.com
(which you should purchase on CD, not via download)
is a fairly unique utility which will create a new, perfect copy of your hard drive's invisible directory. (The thing that allows your computer to keep track of what's on your Mac and where.) The hope is that once your directory is fixed, your problems will be gone.

In this case you won't be "installing" Disk Warrior; instead you will just startup from the Disk Warrior CD by booting with the CD inserted and the "C" key held down. You can then run Disk Warrior from the CD to repair your external hard drive.

Also Randy, the computer shuts down without removing the hd which shows that it's not running, correct?

Hmmm...I'm not sure what that shows.

I have to be honest, I'm not entirely sure that running Disk Warrior will help. It is a good sign that the drive previously has run perfectly on your system. However, you have erased the drive and it still isn't functional. The error messages that you have been getting lead me to believe that the drive may be damaged (with respect to the software on it, and maybe even with respect to the hardware) at this point so that a directory repair utility might not be sufficient to help.

A couple of important questions:
Is the drive still under warranty?
Is there important data on the drive that isn't backed up?

If the answers are "yes" and "no" respectively, then the best course is probably just to return the drive for a new one under warranty. There is no reason to throw money at this problem in that event.
 
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