How can you change read only permissions on an external hard drive on a Mac?
Question by Violeta Hernandez /

I have an Iomega 500 G and making some changes on it. What I must change is the permission. Now it is read only, so no adding anything, even if I know the password.

How can I take this away with out taking the data off? I have no space on my laptop to back it all up. Thanks !

Ads by Google
Browse other questions & answers in the category , ; tagged , ; or ask your own question.

Comments for this Question are closed.

If you are looking for help, please ask a new question.

We will be happy to help you!

Answers (14)
  • tribu13

    hi
    I guess the UUiD solution may have worked. Otherwise, see chown. Remember your mac is a Unix machine…

  • Shane

    I just bought a new external hard drive and had just recently switched over to mac from pc. I was using another external and was trying to copy over all of my files from the old to the new drive. It said “read only” and I couldn’t save. So I found out that I had to format the external hard drive on a pc to exfat and then I could read and write on a mac. be careful that you have all files backed up on the external you are formatted because it wipes everything clean.

  • Steph

    Encountered a similar problem with 2010 MacBook pro & 2TB WD HFS+ My Book.
    The actual folder that showed up under “devices” was completely inaccessible & the permissions for admin, system, & everyone were set to deny access to all & couldn’t be changed even with my admin password.
    I was able to access backup capabilities via time machine & the smart backup software the drive came with, but it turned out I’m only able to access the drive drag & drop files via the icon for the drive that /sometimes/ appears on the desktop. Utterly confusing especially since the instructions included with the device was a tiny 3 page Ikea guide equivalent.
    For future reference, anyone with a better knowledge of these things care to explain why I was unable to change access settings for the drive as a device folder?

  • Alex

    i had the same problem with my external hard drive (1TB seagate NTFS format) and i learned that there was a file called “mac installer.dmg” that would install the program that would allow my computer to read AND WRITE on the hard drive (this program is the same that ha14 has provided a link for). This program came free on my hard drive.

  • Josh

    Hey, I don’t know if you are still finding a solution, but Mac’s can’t write to NTFS (well, they can, but just to keep it short, newer macs can’t natively read/write).

    http://howto.cnet.com/8301-11310_39-57401784-285/the-best-ways-to-format-an-external-drive-for-windows-and-mac/

    That has your answer.

  • Amy

    I am having the same problem but there doesn’t seem to be any option to change the permissions in Info, it just says ‘You can only read’. And in Disk Utility it doesn’t give me the option of Repairing Disk Permissions – the button is transparent and won’t let me click on it. Help??

  • ha14

    run “Repair Disk” on the external drive to make sure it’s file system structure is in tact.
    Applications –> Utilities –> Disk Utility. Then simply select the drive you want to fix:
    click on the “X” drive, then on the button Repair Disk Permissions
    Wait for finish

    • ivan

      none of the buttons is active, they are all greyed out.
      i really need help with this.

  • Mike

    1. select the external hard drives icon
    2. right-click > Get Info (cmd + i)
    3. expand the Sharing & Permission column
    4. click on the lock at the bottom right
    * You will be prompted for an administrator name and password.
    5. once unlocked change the permission for user, group & everyone to read & write
    6. click the little gear right below and select “Apply to enclosed items…”