External drives mount as read only

I am running OS X 10.6, on a MacPro. Something happened recently to make my external hard drives mount as read only. The only way I've found to be able to fix them is to run Disk Utility every time I start up my computer. Does anyone have an solution to this?
Also every time I run the Disk Utility, at the end of the repairs it says "Updating boot support partitions for the volume as required." I do not know if this is related, but I haven't been able to find anything relevant in relation to my problem with the drives mounting as read only.
Message was edited by: HeatherK

You might give this a try:
Select the drive and Press COMMAND-I to open the Get Info window. At the bottom open the Ownership and Sharing section. Be sure the box labeled "Ignore permissions on this volume" is unchecked. If it is checked then click on the lock icon, authenticate, then uncheck that box. Close the window.
Open the Terminal application in your Utilities folder and at the prompt enter or paste the following:
sudo chown root:admin
Put a space after "admin" then drag the drive's icon into the Terminal window. Press RETURN. You will be prompted to enter your admin password which will not be echoed.
See if this fixes the problem.

Similar Messages

[kinda solved, hd broken]Salvaged hard drive mounted as read-only

My old netbook died recently (if a guy in a shady computer store in Edinburgh tells you that "this adapter will surely work" -- what ever you do, don't believe him). Got a new netbook, and an external usb hd case for the old hard drive in the hope of salvaging it.
The old hd seems to have survived, as it mounts just fine and all my old partitions show up (home folder, root, swap...). However, I cannot change the permissions of the files using thunar as root, nor can I copy them to my internal hd --probably because the drive is mounted as read-only. The /home partition, which is the one I'm interested in copying things from, is formated in ext4.
I'm guessing I should change something in my fstab, though I'm not sure what exactly. What's weird though is that the drive does not show up when I run sudo fdisk -l, nor does it show in gparted (which is run as root, of course) -- meaning I don't know what rule I should put in my fstab file, as I dont know what mount point to apply it to. I use xfce on my current laptop, but seeing as the problem persists when I try on my partners ubuntu laptop I figure that the DE hasn't got much to do with it.
I guess I could open up the computer, put in the old hard drive and change some configs, install drivers etc. to make my new computer boot properly from it. Does seem like a drag though, so I figured I'd try asking here first. I suspect this is a fairly common problem, but my google-fu does not appear to be strong enough as I've failed to find a solution on my own.
Last edited by caligo (2010-07-19 20:09:01)

karol wrote:'mount: /dev/sdd2: cannot read superblock' is quite different from mounting read-only - I'd call it read ... NOT!
I hope you have some sort of backup.
Yes, "cannot read" is indeed a more disheartening message... When trying to copy the files through thunar, I can see them but not move or open them -- and trying to change the permissions results in an error message about the file system being "read-only".
itsbrad212 wrote:# fsck /dev/sdd2
results in
Attempt to read block from filesystem resulted in short read
The thing might indeed be dead...
I have backups of all the important things -- just wanted to save some recent random files and a bunch of wallpapers, but I think I'll survive the loss. Thanks for the help guys. Might try to format the whole thing, see if its just the data that's corrupted or of the harware is busted as well.

All USB drives mount as read only for user

I have searched a bunch and thee results I find seem to be irrelevant to my situation. Most relate to a single USB media that is a problem and won't read or write.
On a new Arch install on a new computer (my third base system install). Running Gnome.
All USB mass storage devices mount as read only for the logged in user. Root has write permissions and I can mkdir no problem. It is not an issue with the USB drive itself as this occurs with multiple USB media (I've tested several SD cards on a reader and at least two drives, all the media works correctly on my existing installations)
I'm posting the contents of my /etc/group file in case there's an obvious error there I don't see, and my dmesg output upon plugging in the drive. User name is changed in the group file posted to "archie"
This is a single-user system.
/ect/group
root:x:0:root
bin:x:1:root,bin,daemon
daemon:x:2:root,bin,daemon
sys:x:3:root,bin
adm:x:4:root,daemon
tty:x:5:
disk:x:6:root
lp:x:7:daemon
mem:x:8:
kmem:x:9:
wheel:x:10:root,archie
ftp:x:11:
mail:x:12:
uucp:x:14:archie
log:x:19:root
utmp:x:20:
locate:x:21:
rfkill:x:24:
smmsp:x:25:
http:x:33:
games:x:50:
lock:x:54:
uuidd:x:68:
dbus:x:81:
network:x:90:
video:x:91:
audio:x:92:
optical:x:93:
floppy:x:94:
storage:x:95:
scanner:x:96:
power:x:98:
nobody:x:99:
users:x:100:archie
systemd-journal:x:190:
archie:x:1000:
avahi:x:84:
polkitd:x:102:
rtkit:x:133:
gdm:x:120:
brlapi:x:999:
kvm:x:78:
ntp:x:87:archie
dmesg output
[ 968.044188] usb 4-3: new high-speed USB device number 4 using ehci-pci
[ 968.170628] usb-storage 4-3:1.0: USB Mass Storage device detected
[ 968.171435] scsi7 : usb-storage 4-3:1.0
[ 969.174450] scsi 7:0:0:0: Direct-Access Generic USB SD Reader 1.00 PQ: 0 ANSI: 0
[ 969.175068] scsi 7:0:0:1: Direct-Access Generic USB MS Reader 1.03 PQ: 0 ANSI: 0
[ 969.939417] sd 7:0:0:0: [sdb] 15572992 512-byte logical blocks: (7.97 GB/7.42 GiB)
[ 969.941028] sd 7:0:0:0: [sdb] Write Protect is off
[ 969.941037] sd 7:0:0:0: [sdb] Mode Sense: 03 00 00 00
[ 969.944664] sd 7:0:0:1: [sdc] Attached SCSI removable disk
[ 969.945509] sd 7:0:0:0: [sdb] No Caching mode page found
[ 969.945517] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[ 969.952682] sd 7:0:0:0: [sdb] No Caching mode page found
[ 969.952693] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[ 969.956396] sdb: sdb1
[ 969.965003] sd 7:0:0:0: [sdb] No Caching mode page found
[ 969.965011] sd 7:0:0:0: [sdb] Assuming drive cache: write through
[ 969.965015] sd 7:0:0:0: [sdb] Attached SCSI removable disk
I'm sure I'm just missing something in user management, but I can't find what.
Last edited by hooya (2014-04-27 03:10:49)

I am also having the same problem. Root can read and write to automounted drives, but my user cannot. I've tried with a variety of drives, I am assuming they are being automounted by root instead of the logged-in user somehow. (I am running x directly, and am not using a display manager, if that has anything to do with it).
When I look at how it is mounted it is as follows:
/dev/sdc1 on /run/media/myuser/drivename type vfat (rw,nosuid,nodev,relatime,uid=1000,gid=1000,fmask=0022,dmask=0077,codepage=437,iocharset=iso8859-1,shortname=mixed,showexec,utf8,flush,errors=remount-ro,uhelper=udisks2)

External drive reverts to read-only on reboot

My 2TB firewire drive becomes a read-only drive after a computer reboot. From a cold start, drives boots to read-write. How do I fix this?

Nicky McCatty wrote:
Earlier this morning my external drive, a Western Digital Firewire 800 1TB, was behaving normally. I shut my MacBook Pro down, and took it out for two hours. When I returned, Time Machine reported that my drive appeared to be read-only. I see that BOTH of my external Firewires now show up as read-only.
What causes this to happen, and what can I do about this problem?
A number of things. Most common is probably a power loss; second is probably disconnecting without first ejecting.
It's not permissions; try running +*Repair Disk+* on them, per #A5 in Time Machine - Troubleshooting (or use the link in *User Tips* at the top of this forum).

After moving iTunes, external drive sometimes becomes read-only after reboot

I had some system corruption a few weeks ago, and had to restore my system. As part of that prolonged effort, I decided to move my iPhoto Library and iTunes Library to external FW800 drives.
I had terrible problems initially with these drives mounting read-only. I found a relatively quick work-around, and that seemed to fix the problem. But I still have them periodically mount read-only, and I can't D/L iTunes updates, etc.
Why do they keep doing this on a reboot? Very frustrating, as I need to reboot as part of the fix, and I'm always in the middle of something else, and can't reboot at that time.

Oh, as part of this, not sure when the change was made, OSX used to keep the mounted volume name in /Volumes, even if the volume was ejected. Would cause an occasional problem - but very rare. I notice now that ML seems to create/delete these mountpoints automagically - and that's part of the problem. They get incorrect permissions when the volume mounts, and I (user I'm logged in as), can't write to the volume without some background shenanigans.
My process is this:
Unmount problem volume
Drop to terminal, and "sudo mkdir /Volumes/<mounted_volume_name>"
Remount volume via Disk Utility (you now get a "<mounted_volume_name> 1" - with CORRECT permissions)
Unmount the volume again
Remove the created directory (i.e. undo step 2)
Remount the volume - 99.9% of the time that seems to fix it.
Reboot to be sure - and it stays for a while - then at some point becomes a problem again.
Not sure if it's something in ML that's an issue - or something in iTunes or iPhoto (but can't see how they would affect the permissions when the system reboots and you login)

External drive changed to read-only

I have a Western Digital external drive that I use for Time Capsule and Super Duper! This morning, when I wanted to start work, Time Capsule said that my drive "appears to be a read-only drive," and Super Duper had failed its overnight backup.
I used BatChMod, and changed the permissions.
When I opened a finder window for the external, it still showed the read-only icon in the lower left hand corner of the window.
The Get Info window shows System as the owner, Admin as the group, with all permissions. EVERYONE has read-only permission.
When I look at the disk in Disk Utility, Repair Disk Permissions is greyed out.
What would change the disk's status, and how can I fix this?
Thanks,
Nicky

Most likely, your backups were corrupted, beyond Disk Utility's ability to repair them. It's possible a 3rd party disk repair app, such as +Disk Warrior,+ could have fixed them, but it's too late now.
Does the drive have two partitions, one for Time Machine backups, and a second for SuperDuper? If so, erase the Time Machine partition and let TM start over.
If not, that's a problem (see #3 in the Frequently Asked Questions *User Tip,* also at the top of this forum). Your best bet is to reformat the disk with two partitions. See #5 in the FAQ for detailed instructions. Then start both Time Machine and SuperDuper over fresh.
Longer-term, having both backups on the same physical drive is not good; if the drive fails, you risk losing both of them.

External drive is suddenly read-only, yet is formatted for Mac

I've had a 1TB external hard drive for the last year and never had a problem with it until now. Suddenly, it is showing as read-only, however, it's formatted for Mac. How am I able to fix this? Do I have to re-format it?

Usually that means the drive is malfunctioning. Back up all data on it, if you haven't already done so, then erase and restore. If you ever have another problem with the drive, replace it.

External drive reverts to read-only on airport extreme

I have an external drive that works fine (full access read/write) when connected directly to my Macbook but reverts to read-only when I connect to it through my airport extreme. It also won't let me change the permisssions over the network. I have another drive used for Time Capsule connected to the Airport Extreme and it works fine, as well as the printer. The problem drive is formatted OS X extended (journaled).

Nicky McCatty wrote:
Earlier this morning my external drive, a Western Digital Firewire 800 1TB, was behaving normally. I shut my MacBook Pro down, and took it out for two hours. When I returned, Time Machine reported that my drive appeared to be read-only. I see that BOTH of my external Firewires now show up as read-only.
What causes this to happen, and what can I do about this problem?
A number of things. Most common is probably a power loss; second is probably disconnecting without first ejecting.
It's not permissions; try running +*Repair Disk+* on them, per #A5 in Time Machine - Troubleshooting (or use the link in *User Tips* at the top of this forum).

[solved] External drive automatically mounted as read-only

Hi folks,
I have a strange issue with an external drive automatically mounted as read-only whenever I plug it to my laptop :
[sclarckone@archLaptop ~]$ mount
/dev/sdb1 on /run/media/sclarckone/dd type ntfs (ro,nosuid,nodev,relatime,uid=1000,gid=100,fmask=0177,dmask=077,nls=utf8,errors=continue,mft_zone_multiplier=1,uhelper=udisks2)
And I can't remount it as read-write :
[sclarckone@archLaptop ~]$ sudo mount -o remount,rw /dev/sdb1
mount: cannot remount /dev/sdb1 read-write, is write-protected
But of course, I'm able to mount it as read-write on other operating systems.
I have udisks and udisks2 installed on my system. I also belong to the storage group so I thought I could mount a filesystem as a normal user but I can't :
[sclarckone@archLaptop ~]$ mount /dev/sdb1 dd/
mount: only root can do that
I don't know whether it is relevant to this problem, but I have systemd and polkit installed as well... Does anybody has an idea of where the problem could come from ?
Thanks for your help !
Last edited by sclarckone (2012-12-13 21:45:04)

Check out following file :
/usr/share/polkit-1/actions/org.freedesktop.udisks.policy
Look for mount a device and It should have configuration like :
<action id="org.freedesktop.udisks.filesystem-mount">
<description>Mount a device</description>
<description xml:lang="da">MontÃ©r en enhed</description>
<message>Authentication is required to mount the device</message>
<message xml:lang="da">Autorisering er pÃ¥krÃ¦vet for at montere et fil system</message>
<defaults>
<allow_any>no</allow_any>
<allow_inactive>no</allow_inactive>
<allow_active>yes</allow_active>
</defaults>
</action>

External hard drive suddenly become read only

For those who have been using an external hard drive on OS X (using NTFS file system) without any problem and suddenly one day the system has started mounting it as a read only file system, this is because the file system right now has some inconsistences.
As it happened last night to me i started googling for a quick solution to solve the problem. But i didnt find anything out there. At least at first glance. So then i checked the system logs of the system in order to get some sort of specific information about why that was happening (in OS you have an application that makes so easy to have a look through the system logs and its in /applications/utilities/console.app). In my case, and i repeat, IN MY CASE, the problem was the following:
21/07/11 18:59:02 kernel NTFS-fs warning (device /dev/disk1s1, pid 2140): ntfs_system_inodes_get(): $MFTMirr does not match $MFT. Will not be able to remount read-write. Run ntfsfix and/or chkdsk.
So afterwards once known the problem, was as easy as to mount the external HD in windows and execute the command chkdsk /f (google about the usage of the tool if dont know how it works).
Alternatively, you have the Linux option using the ntfsfix command, but you will need to install the program before that (if dont have it previously in your system) or otherwise you won't be able to use it (sudo apt-get install ntfsprogs)
Hope it helps.
Marc

I got an error message that my External Hard Drive was now 'read only'. Having scoured the various forums looking for clues as to why it had happened I found numerous suggestions, all of which seemed overly complicated and beyond my basic understanding (I'm old enough to remember when Macs 'just worked').
Anyway, among the suggestions on how to correct this I found what seemed like an overly simplified one - 'Don't switch on your external hard drive until after you've booted up'. Since I tend to leave mine on all the time, I immediately turned it off and back on again and ran Time Machine in hope rather than expectation. Would you believe it? It backed up as normal first time. Hope it works for anyone else having the same problem.

[Solved]External HDD only mounts as read only

Okay, I have a general log, but I'm not completely sure what all information you need. Ask and you will receive.
So I run udiskie through i3, works great, but my file systems get mounted as read-only, which is..not great. It's pretty irritating. So I thought, hey, let's just chown that shit, right? No. It's a read only file system.
Anyway, so I did killall udiskie, tried mounting it manually and all as demonstrated in lsblk, and it's still read only, for some interesting reason. (Sorry the lsblk log isn't clean). If there's some other output you'd like, let me know...
I run the thunar file manager, which is alright, but it doesn't auto-mount (I tried setting it up, googled it a lot, it just didn't auto-mount, and udiskie looked like it worked fine until I realized it was all read-only).
In lsblk I ran sudo thunar to view the drive, since permission was denied to myself. It was still read-only, meaning it's not necessarily a udiskie problem? I could mount my other flash drive alright it appeared, but when I did it with udiskie it was also readonly.
The flash drive was made with dd, so it had two partitions, the second one mounted fine, the first one not so much, and with udiskie it just mounted what looked like the second one with more files (So maybe both? I was a bit confused).
lsblk: http://pastebin.com/WdJbky9j
udiskie -a: http://pastebin.com/RT2sQE01
On a side note, those awesome arrows on the side of my terminal thanks to zsh and oh-my-zsh? They're just empty rectangles in rxvt-unicode, and I have no idea why. They display fine in pastebin. If anyone happens to know what I'm missing there, much obliged.
Solution:
Actually understand NTFS in linux (Working on it)
Install ntfs-3g
Last edited by Rojikku (2014-07-02 02:06:18)

lsblk -f: http://pastebin.com/KeHpDtF6
Anything I could say would be repetitive of the data. >>; But for record purposes, btrfs and the external is ntfs.
Edit: I don't have ntfs-3g installed, FYI. It seemed like an alternative to udiskie and I dislike installing things frivolously. I noticed another user fixed a somewhat similar problem like that, would that be my issue?
Last edited by Rojikku (2014-07-02 01:37:24)

I have a FAT 32 External Hard Drive marked as Read Only that is unchangeable by an administrator or root user, how can I make it read/Write

Hello, All,
I have a FAT 32 External Hard Drive marked as Read Only that is unchangeable by an administrator or root user, how can I make it read/Write without reformatting it ?

Hi Kappy,
Just wondering if you had any advice for my situation . . .
My time machine backup was backing up to a drive that was "Mac OS X Enteded Journaled, Case Sensitive." I had no idea what this meant, or that it would even cause issues.
I took my computer to the Apple store yesterday, and they wiped it clean. When they tried to restore it from the Time Machine backup drive, it would not work. Their guess is that Time Machine cannot restore from a drive that is "case sensitive."
Any thoughts on how I can convert my time machine backup data from a "case sensitive" state, to a "non-case sensitive" state? I've tried to just drag and drop the files from the case sensitive formatted drive to a new drive that I have that is formatted non case sensitive, but I get the following error message:
"The volume has the wrong case sensitivity for a backup"
I just really want my data back - I thought TimeMachine was the way to go (and was supposed to work) but unfortunately it is not.
Any help you can provide would be greatly appreciated.
Thanks,

Why does my external drive mount as not writable?

I've got a 1 TB external WD drive formatted as Mac OS Extended. After upgrading my MacBook Pro this drive occasionally is mounted as read-only. If I open Disk Utility and Verify the volume, the verify completes without reporting any errors, and when it remounts the volume, it's writable again. Anyone else seen this behaviour?
-Brian

You may try a SMC reset, maybe do it 2-3x.
SMC RESET
Shut down the computer.
Unplug the computer's power cord and all peripherals.
Press and hold the power button for 5 seconds.
Release the power button.
Attach the computers power cable.
Press the power button to turn on the computer.

My mac mini won't back up to my Seagate external drive but can read the information on it. Can i back up to it at all?

My mac mini won't back up to my Seagate external drive but can read the information on it.
Can i back up to it at all? and how do i do it?
Simon

I suspect the Seagate is not formatted to be used with the Mac. The correct format would be Mac OS Extended (Journaled), if you just bought the EHD then almost certainly it's formatted to be used with MS Windows machines. This is easy to fix, here are instructions on how to format it:
http://pondini.org/OSX/DU1.html
After formatting Time Machine http://support.apple.com/kb/ht1427 will launch and will begin backing up. The first backup will take some time however after the first backup it will go pretty quickly.
NOTE!!!!!!!!!!!!!!! After formatting all data will be erased, so please if you have data on that move it to the internal HD first and then format. Then once you have backed up you will have a backup copy of the data. Also NEVER EVER use a backup disk to be used to store data. The reason being is if that drive crashes you have not only lost the data you have lost it's backup!!!!!!!!!!!!!!!

Drive changes to read only

I am new to mac. I have a new 27" IMac. I purchased this computer strictly for photo processing
I have 3 external drives
1. Time Machine backup - Seagate 3TB - No problemn with this drive right out of the box
2. Photo Drive - Seagate 2TB Firewire drive- Photo library is 1.4TB
3. Original Photos -Seagate 2 TB USB drive Small amout of data but have used this for backup while reformating the photo drive
1TB Internal drive that only contains the OS and Programs. Mainly Adobe Lightroom and Photoshop
The Photo Drive was purchased as ready for PC or Mac
I pluged it in and it worked just long enough to load all my photos and get things organized.
The 2TB Original Photo drive was originall used for PC and I discovered I could not write to this drive so I reformatted to OS Journaled.
Next, My main Photo drive became read only - Error message stated I need to refornat the drive - Error 36
I transfered all Photos to Original, Reformated Photos as OS Journaled and then transfered files from Origianl back to Photo
All sorded for a a couple of weeks then the Origial drive became read only and I have to format it again.
Since then, the photo drive has become read only two more times.
I just finished reloading the photo drive for the third time on Thursday. For the last 3 days I have been Importing new photos from several weeks of shooting.
All seemd fine untill today. I tried to create a folder and discovered the photo drive is once again read only. The Original photos drive is still read / write.
I have read everything I can online. It seems other people have had similar problems but I found no solutions.
Currently the photo drive info is as follows
Flormat Mac OS Extended - I'm sure I selected Journaled on the last format
Sharing and permissions
"You can only read" is at the top
followed in black text
     Paul (Me) Read & Write
     Staff Read & Write
     Everyone Read & Write - (I changed this after formatting and before reloading the drive thinking it might help)
     Ignore ownership is checked
I can unlock the pad lock Icon but I cannot change anything except I can uncheck and recheck Ignor ownership. However this still does not allow me to make any changes.
One clue I may have to offer
I use a small Seagate drive named Transfer Drive which I use in the field.
It is formated NTFS
I download photos from my photo cards to my PC notebook and back them up to the Transfer drive
When I get home I import photos from the Transfer drive to my iMac using Lightroom
This was the last action I performed yesterday. I performed 8 imports from the Transfer drive to My imac with Lightroom
Is it possible that importing from a NTFS drive to the external Photo drive is causing this problem?
I really need to solve this. It takes about 3 days for me to move my photo library and reformat the drive
Not to mention the fact that I am very worried about my photo files.
Thank you in advance
Paul McCroskey

There may be a solution here, but I would modify the instructions to say that if Verify disk shows OK, you don't need to go on to Repair.
https://discussions.apple.com/message/18266486#18266486
First, copy/paste, leave a space after -alO and drag Photos into the Terminal window and hit return.
ls -alO
If the output shows the uchg flag, the immutable (locked) flag, then run the following to remove it.
sudo chflags nouchg /Volumes/Photos
If that doesn't fix it, then Verify Disk. If that shows an error, then follow the instructions to copy the data elsewhere first, then run Disk repair. Sometimes, though this is rare, disk repair can make things worse.
(After removing the immutable flag -- if it proves necessary -- you may still have to go on and run the commands you tried earlier.)

External drives mount as read only

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