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Why is my Mac hard drive suddenly read-only?

Hi Dave, I am running Mac OS X 10.3.9 and recently encountered a strange occurrence. Instead of the usual tag under my main hard drive(74.4 GB, 24.75 GB used) it shows (74.4 GB). After I used "Get Info" it says i have read-only access. Every time i want to move a file to it, it asks for my admin password. I am normally an admin user, and this has never happened before. Is this a major thing? And how can i change it back to what it was before?

Dave's Answer:

That's a very strange occurrence, I agree with you. The good news is that one of the standard administrative applications included with Mac OS X will doubtless fix what's happened on your disk, which is that a folder permission has somehow been messed up.

The program you need is Disk Utility and you can find it in Applications --> Utilities --> Disk Utility. Then simply select the drive you want to fix:

Click for full size screenshot

In this case, "X" is my boot drive, and "X2" is my backup drive. I clicked on the "X" drive, then on the button Repair Disk Permissions.

Now the utility will go through the entire file system, making sure that the access permissions and ownership of each major directory matches the recommended configuration from Apple. It'll take a few minutes, during which time you'll see information like:

Finally, it'll be done and I bet your problem will be fixed!

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Categorized: Mac OS X Help (Article 6396)
Tagged: disk troubleshooting, mac os x, repairing permissions
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Comments

I tried this and it didn't work. Not complaining, I appreciate free advice, but I though you'd like to know.

Posted by: paul miller at June 9, 2006 6:59 AM

I have an external hard disk drive that is 400gb and it says read only for the mac but it lets me edit files on it on my pc!? Any help would be really appreciated.

Posted by: Oliver Tappin at April 25, 2007 1:00 PM

Hello there, i agree with davem you do need to format it but its also to do with fat32 and NFTS! Macintosh computers only work woth fat32 and windows have come up with their one that they have made which is much faster which is called NFTS. If you want to use your external hdd with mac and pc, then you need to format it on the mac, which will automaticly put it to fat32 but if you format it on pc, make sure it is set to fat32 and NOT NFTS. NFTS only works with windows, even though its really fast and works well, fat32 works with mac and pc. If you have any problems, i would be happy to help. Hope that helps anyone here!

Posted by: Ollie at May 20, 2007 11:59 AM

i can no find my hard drive
my hard drive is lost

Posted by: roberto at May 30, 2007 10:03 PM

Is there a way of making it FAT32 without loosing all your data on the hard drive?

Posted by: Matt at August 15, 2007 7:27 AM

Hi,

I have the exact same problem,
My 'Repair disc permissions' is greyed out..

Any Ideas..?

Posted by: Mike at January 24, 2008 2:13 PM

Hi ,I am Aditya from India .I have a problem that I am unable to solve and know the root cause.My system stops suddenly (while browsing ,listening music ...etc)i.e just like a movie been paused ,then i restart my system using power switch.It just shows a blank screen and my hard disk makes a kink sound at the beginning and then it goes on reading and reading but blank screen remains.
My details: Motherboard Intel 915GAV ,
Processor Intel 2.8GHz HT, HDD :Seagate Sata ST3160215AS_____________________________3.AAD___\5&30D26B9&0&0.0.0
RAM: 512MB . OS :XP+sp2
3 years old and motherboard been replaced twice due to above reason.
I have removed my cables and then reconnected and the problem is solved ,but at times I have to reconnect more than 10 times and even 2 days .Then it starting booting and starts normally .I am unable to know the root cause .I am regularly installing latest OS after 6 months.

Posted by: Aditya at January 25, 2008 9:08 AM

This was all great, until the Restore button was greyed out.

Your advice was simple and clear, just left me at a dead end.

You can email an answer if you figure it out at rswild@gmail.com

Thanks,

Scott Wild

Posted by: Scott Wild at February 12, 2008 10:49 AM

I have a lot to say, but ...

I have a lot to say, and questions of my own for that matter, but most of all I'd like to say thank you for all your efforts on this Web site by buying you a chai!

I do have a comment, now that you mention it!