External Hard Drives Changing Permissions to Read Only

To Kappy or who ever else can help,

Today is May 6th and I have the same problem as everyone else. I have had this rocstor T1 HD and have only used it with my 13" Macbook Pro OSX 10.6.7 I was just using it yesterday in my graphic design class with my laptop and this morning it says read only on me (admin) and read only on everyone. I can pull files from it, but I cannot write files to it. I do not have any option check boxes and all selections are greyed out. I'm a little confused why this suddenly happened. one curious part is that the info of my HD says i have 2 partitions, what does that mean. im a graphic designer and mac lover, but I'm no expert in these matters.

A LOT of help would be greatly appreciated.

Thank you for your time,

Zen

To all aboard having this problem... OSX has a major problem on its hands. I too had a 2 TB Seagate external hard drive formatted Mac OSX Journaled and it had been working fine. Now, problems. It has grayed out all ability for changing permissions within the "info" field, and is only read only now. It started out with the "lost + found" folder showing up all of a sudden on my Seagate hard drive (which I believe is a Unix folder that shows up when problems of corruption are occurring when trying to mount a unix formatted drive). This "lost + found" folder had a no access setting on it, and I was able to change the permissions on it, and I erased it from the drive. Then after moving a few more movies around, and plugging and unplugging the drive a couple of times (properly ejecting it every time) it has grayed out all the permissions and the checklist. I cannot erase or add to the drive.I can however drag files off of it.

Now, let me explain exactly what I was doing with this drive. It was almost full (maybe 2 gigs left open), and I was dragging a 20 gig movie from it over to a 3 TB WD external HD. The Seagate drive was plugged into the Apple keyboard USB port, and the WD drive was plugged into the usb port on my G5 tower. Everything had been fine for months and months before. What is going on with OSX? Is this an official bug?

Verifying the drive with Drive Utility has done nothing (unlike what a previous post has said) and no offense to anyone here, but there is no way in h*ll I'm opening up terminal to do anything with this drive. I've got over 400 movies on this thing and I should not have to open up terminal to do anything with it.

Thanks! I had the same problem; external USB HD suddenly was Read Only.

This worked for me:

Step 1 - Open Disk Utility

Step 2 - Clicked on the Disk I was trying to fix.

Step 3 - on the Bottom Right hand side there is an option called Verify Disk.

Step 4 - Make sure the external HD is connected directly into the USB not through a hub.

Step 5 - After a long verifying process, both my external became read/write!

The Verify Disk trick has worked for me.

Another one that has worked in the past is to log out of the user account (Apple menu, last option) and then log back in to the same user you just logged out of.

I don't have any idea why either workaround works.

I administer about 10 computers that are primarily used for Final Cut Pro and they all use G-Tech drives for media. This problem started happening on all of them, and I think it either has something to do with upgrading to 10.6.7 or 10.6.8, or it has something to do with sharting preferences / screen sharing settings we started monkeying around with.

This morning we had an Avid Unity (which is a SAN, I think) partition have the same problem, and you can't verify those disks... so it is starting to worry me. The user had resarted the computer a couple of times, and that fixed the permissions issue for now.

settings can be weird and things can get corrupted. This is why that 'verify disk' trick works. It forces the system to recheck all the various settings like how the drive is formatted, is there a proper directory and so on.

And yes sometimes things can go wonky when you are doing OS updates (especially if you are doing a big one like Snow Leopard to Lion) or turning sharing on and off.

That said, if this media is mission critical it is a very very good idea to have a second copy of it. Whether it is another hard drive or keeping the original digital cards/tape.

Just came upon this thread due to hiccup with my macbook pro last night; my OS glitched unexpectedly with thin blue lines across the screen; it restarted and seemed fine; this morning when trying to save to my external Seagate drive I came upon the mysterous "write only" condition mentioned by others; tried the most simple out: I ejected the hard drive; unplugged the USB and replugged it; this unplug/replug refresh seemed to work; the macbook pro now "sees" the drive as both write and read; whew!

Thanks for all the other insights offered.

Hello everyone... before I make a complete fool of myself I just wanted to say that I am a complete noob when it comes to these things so please be gentle 🙂

I suddenly had the same problem where my external HD changed permissions to read only (it has been working fine for the past 3 months). Under the "Get info" tab "Sharing & Permissions" section it only reads "you can only read" with no other info. No mention of the users or any other info and I can't click or hit anything (other than my head against the wall!!!!) If I try the Desktop Utilities route my Macbook Air recognizes the eternal hard drive but all buttons such as "verify Disk" etc are greyed out... no idea what I should do. Tried logging out of my user account and back in, tried ejecting and reconnecting but everything has failed.

Anyone with any ideas?! please need any help I can get. Thanks!

Have you tried actually restarting the computer. Logging out doesn't clear things fully the way that a restart does. Or even just try ejecting and reconnecting the drive. I've seen both of these work for folks

yeah I've also restarted several times... for some reason now when I look at the "get Ino" tab, its reading that the HDD is NTFS, can it just change? I haven't done anything since I bought the HDD... On purhase I reformatted it to play both pc and mac... this is just the weirdest thing

Very simply, I discovered the other day that several of the Firewire drives in my chain had become "Read Only" drives.

Searched the internet for an answer and landed here.

This has never happened to me before in all my years of owning and using Macs. (Since 1988)

The solution for me was simply opening Disk Utility and Verifying the disk(s) in question.

Each time I Verfiied the problem was corrected.

I tried the other suggestion of using Terminal and doing that fancy foot work thing. It did not work for me. Tried it on 2 drives....Nothing happened.

Verify using Disk Utility and let me know what happens.

I read this thread hoping to get a suitable answer to a problem I was having with an SD card. I've got to say that your ignorant attitude (admittedly a year ago) to others really surprised me. Shame on you!

Unfortunately none of the information gleaned from this thread has helped solve my own problem, so I will continue searching.

Dear friends,

I am facing a problem with my External HDD formatted in FAT32 file system.

I have an external HDD that is formatted in FAT32 file system and I want to share this drive on my network so that my other MAC user can access this external drive.

I have two MAC mini with OSX 10.6 and 10.7.3 and one MAC Book pro with 10.7.3. All are on same network able to see each other share Drives. But they are only able to access the Public folders of all the users and Internal HDD of all the MAC books. They are also able to see shared external HDD but no one is able to open that external drive over network. Only the MAC book with external drive is directly connected is able to open it and make file and folder in that.

I have also noticed one issue with this external HDD whenever I try to share this drive via file sharing option its user permission is not highlighted.

Could anyone help on this matter how could I access this drive from other MAC book.

Please revert on my post if any have any suggestion on my problem.

I am having the exact same problem with my external drives, WD and FreeAgent. Unable to change so I can write to any of the drives any more. Surely as someone suggested before this might just be a problem with Mac OS System somewhere. Very frustrating.