Why is my Mac hard drive suddenly read-only?

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

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.

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!

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

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

Hi,

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

Any Ideas..?

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.

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

FYI fat32 is only good for 2 gigs

but on the reformating thing...windows only lets mac read its files (nfts), not write...that includes washing it down(for older systems anyway)...ik i can on leopard...

but for sharing..well i like to keep my dirty mp3s on the mac cuz it can take it, analog record to windows and save on a dif partition on my exhd...then ik its clean 4 good lol

but yea...discs work 2

What David REALLY meant to say is that fat32 is only good up to 4 gigs PER FILE( NOT PARTITION!)

Otherwise anyone that buys a Western Digital portable hard drive will be confused why their 100+ gig hdd is fat32...

But I did find these comments useful. Didn't know ntfs(not nfts, as others put it lol) wasn't writeable on a Mac. It confused me because it works in both Windows and Linux... in Linux it shows that my hdd has 777 file permissions, but when I mounted it on my Mac it only had 755.

hi!

i have a problem... I was trying to lock my macintosh hd and accidentally placed read only for the admin then locked it. i later realised what a disaster it was and decided to restart my laptop. when i turned it on the screen was blank and just loading for almost an hour. i repeatedly restarted it for the day but it wont go to the actual desktop. my laptop has a login and password requirement to get to the desktop. please help me!thanks

Hi Dave,

I have the Final Cut Express 4 software on my imac.Have tried to configure my external drive but am getting the message "unable to set scratch disc.the selected directory is on write protected or non-writable media"
How can I go about configuring it? A step by step explanation will be appreciated very much.

Bernard

I just wanted to add how to do this from the terminal since this site gets all kinds of hits

Machine will not load OS. Reboot
While starting up hold APPLE-S until you see it in a command prompt.

Follow the instructions provided to mount your Volume (doesn't work unless you mount it;)

Now follow the rest:

Type
cd /Volumes
and press enter

Type the command
chmod 755 Macintosh\ HD/
and press enter

sudo chmod -RN /Volumes/"Macintosh HD"/Users/USERNAME
sudo chown -R USERNAME /Volumes/"Macintosh HD"/Users/USERNAME

Please share this with everyone, it's worked a dozen times for me. Apple needs to make it so that we can't mess up an OS from the preferences pane.

i have mac osx tiger and my ibook g4 keeps going into the single-user mode and im not able to get it out of there and start my laptop normally how do i get out of this and make sure it does not go back in there?

So to put it in simple terms

FAT 32 - Works with Mac and PC
NTFS - Works with PC, but Read-only in Mac

FAT 32 - Cannot transfer files > 4 GB
NTFS - Any Size

Final Verdict - You can't have both at the same time.

Am I missing anything?

Your answer didn't work. I can see the hard drive on Disk utility, but I can't select it... Ken

Hi,
Brilliant, worked straight away. Thanks so much for the help.

Hi there,
I'm also facing the same problem here. I've tried all following command, but the messages are still the same, that the file is read-only.
I also tried to startup using single-user mode, but It stops and shows IO error.
chmod 755 Macintosh\ HD/
sudo chmod -RN /Volumes/"Macintosh HD"/Users/USERNAME
chmod: suwandi 1/: Read-only file system
.....

chmod: Failed to clear ACL on file suwandi 1/Users/suwandi: Read-only file system
....

sudo chown -R USERNAME /Volumes/"Macintosh HD"/Users/USERNAME
chown: suwandi 1/Users/suwandi/#.profile#: Read-only file system
.....

Please let me know if you have the solutions

the repair is shaded out, i cant click on it.

Please can you suggest me soemthing!

this command sudo chmod -RN /Volumes/"Macintosh HD"/Users/USERNAME
sudo chown -R USERNAME /Volumes/"Macintosh HD"/Users/USERNAME i did in terminal on a macbook pro i made internal boot drive read only. What do after I put command in. it doesn't change or reboot? I tried commands to exit it stays in black screen single mode. please advise.Thanks

SAme problem - repair option greyed out.

How do I get round this?

Thanks you for the awesome insight Dave....!

I opened up the disk utility but it doesnt give me the option to verify disk permissions or repair disk permissions. Those buttons are unclickable. Help please??

Hi , My 'Repair disc permissions' is greyed out..

Any Ideas..?

Ok I had the same problem "Repair disc Permission is greyed out" As long as you are confident you want to delete everything, click on the erase tab in desk utilities, then click on erase. This erased everything from my external WD hard drive as I wanted.

I have tried the following: Disk Utility - Restore button was greyed out. Then I tried the following commands:

sudo chmod -RN /Volumes/....
I received the following error messages (one per file in the volume):

chmod: Failed to clear ACL on file IMG_0010.jpg: Read-only file system

I then tried
sudo chown -R USERNAME /Volumes/....
I received the following error messages (one per file in the volume):

chown: /volumes/Untitled/IMG_0011.jpg: Read-only file system

It is an SD card where I put a bunch of images onto it for a digital picture frame. After putting it in the frame I wanted to add files to the SD card and this is what I get. No, the SD card is not locked.

Any ideas???

fixed mine like this,right-click wd icon in computer folder,then press properties-tools-check now-start ok. should work 100%.other solutions are useless.

I am facing a similar issue. I can move, delete filed from my primary HD but when I see the permissions in the "get info" on my HD, it says read only. Is it the way it is suppose to be? As far as i remember, i was read & write the last time I saw it. I tried the repair disk permissions thing, it did that but still my HD is in read only mode.

I have another basic doubt, I understood your terminal method but havent tried it because I am wary as the complete steps are not given. I am first time mac user and would appreciate if you could give me all the steps that are to be done on the terminal.

You have to transfer the stuff you want to keep off of the external drive first. Then open Utilities in your Applications folder, open Disk Utilities. Format (Erase) the drive in Fat32. Put the stuff back on it, it should work.

i went to go do this but the "Repair Disk Permissions" button wouldnt let me click it, it was all greyed out... :S

I am having the same grayed out problem with a locked up external drive. Has this question been answered? I see lots of the same question but no link or method of getting Repair Disk Permissions ungrayed.

If you're having problems with the "Repair Disk" option being greyed out and unclickable, it's because Mac OS X thinks it's the boot drive. Boot off your original install / restore DVD (you don't have to install the OS, don't panic!) and choose Disk Utility. Then you should be able to fix it. Done? Reboot and you should be golden.

My External Hard disk was powered and was abruptly powered off while transferring file. when i reconnected the HDD, it connected as readonly. Then i disconnected it and and connected it to windows and then properly ejected it. later when I connected it back to my mac, it worked great and restored all permissions.

I have a similar issue as the OP, and on two separate Macs running OS X 10.7.2. If I want to copy items to or from my Hard disk, I must authenticate as myself, a logged in admin user. I have full rights to my home directory, but I cannot write to my hard disk unless I first authenticate. Hard disk owner is "System", r/w, Group is "Wheel" read only, "Everyone" is read only. Home Dir folder is owned by my name, the logged in admin user. I have ran permissions repair with both Onyx and Disk Utility to no avail. Is there a fairly easy way to correct this problem? I guarantee a SB Venti of your choice with correct answer :) Thanks in advance.

Don, hmmm.... can you open Terminal.app and type in "ls -ld ." to see what kind of permissions and ownership you have? Here's what I see:

$ : ls -ld .
drwx------+ 26 taylor staff 884 Jan 1 08:59 ./

Seems odd, as you say.

hello, i have many questions actually.
they same this happened with me my hard drive is suddenly "read only" and i have opened disk utility but the "repair disk permission" button is greyed out and i cannot click on it, BUT i can click on the repair disk option. if i do will this erase all the data on my hard disk?
help please