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Mike, Mac Support Specialist
Category: Mac
Satisfied Customers: 2186
Experience:  Apple trained Technician, A+ Certified, 20+ years of Mac support, repairs, training, and consulting
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My Maxtor One Touch III Firewire 400/USB 2.0 hard drive wont

Customer Question

My Maxtor One Touch III Firewire 400/USB 2.0 hard drive won't let me add new files to it. I can access the files on the hard drive and copy them to another location, but I can't put any new files on it ("drive cannot be modified").

I had added new files to the drive in September and haven't used it since. Now it won't let me add more, even though there are 229gb of storage remaining.

What can I do?


Submitted: 6 years ago.
Category: Mac
Expert:  Mike replied 6 years ago.

Has this been resolved yet?

If not, go to your Applications folder and open the Utilities folder. In here open Disk Utility.

Click once on the drive in the left side and on the right side, click on Repair Disk.

Let that work and when done, if available, click on Repair Permissions as well.

When finished, quit and unmount and then re-mount the hard drive and test again.

Customer: replied 6 years ago.

Thanks for the information. Although I tried to take the steps you suggested, the screen with the disk repair icon would not let me repair the disk (the icon was disabled). I checked the status of the hard drive using the "information" icon, and it identifies it as not a writable drive. looks like another solution needs to be found.

What could have caused the drive to suddenly become unwritable? Thanks for any other help you can provide.

Expert:  Mike replied 6 years ago.

Let's try this.

On the Desktop, click once on the Drive icon.

Go to the Finder menu and choose Get Info.

Look at the Permissions section. What does it say in there for permissions for each group?
Is there an Ignore Permissions/Ownership checkbox? Is it checked or unchecked (should be checked).

Let me know,
Customer: replied 6 years ago.
All it says is "You can only read."
Customer: replied 6 years ago.
What's also interesting is that says the drive was last modified on April 22, 2009. But I know I also added files on September 4, 2009 and these are clearly on the drive (I can access them). So it seems that something may have happened as I was adding these files (?)
Expert:  Mike replied 6 years ago.

Can you click the padlock, then change that Read Only to Read/Write?

Customer: replied 6 years ago.
Actually, there is no padlock option for the external hard drive, unlike for the computer's internal hard drive. When I "get info" for the computer's hard drive, it does indeed have a tab that says "details", and once you open that, you can click a padlock to toggle the read/write function.

But on the external hard drive, there is only the phrase "You can only read" (under the heading Ownership & Permissions), and no subsequent icon allowing you to modify that padlock, no drop down menu, etc...

very strange...
Expert:  Mike replied 6 years ago.

Yes, that is very strange.

Any chance this drive has a lock switch on it? Like an old floppy or Zip, there was a switch on the disk that you moved to prevent writing.

Does this drive have a physical switch on it that prevents writing?

Do you have another external drive and does it work OK?

Let me know,
I'll keep looking for another solution.

Customer: replied 6 years ago.
The drive does not have a lock switch on it (not obvious anyway). And my other external hard drive works fine...


The last action I did to the problem drive was to copy a large number of files from a server, and most of those files were "read only". Could this somehow have affected the configuration of my external hard drive?

Expert:  Mike replied 6 years ago.

Read-Only files should not do that. It might seem that way if the drive is copying a file and it gets disconnected before finishing, it may have left the drive in a read-only state. Or...

Is there software installed for your drive? Have you gone in there and looked to see if the drive software is actualling locking it and maybe there is a toggle to allow editing again? If you don't have the software installed, here is an updated version from the website.

Run it and then restart, plug the drive in (disconnect from Mac before install), and finish the software install. Then check for a drive manager and see if there is a settings panel/tab or go to the Application menu (it will be Maxtor something) and choose Preferences. See if there is something in the prefs as well.

Otherwise, I am out of ideas here.


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