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Drive permissions to no access for everyone

I set permissions on my drive as no access for everyone. To make it worse I applied to all sub folders. Now mac will not boot. Also cd drive does not work so that is not an option for booting. Any suggestions please - need help

Posted on Jul 21, 2012 4:19 PM

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Posted on Jul 21, 2012 5:10 PM

Hello Angel,


See this User Tip by Niel: I accidentally set a disk's permissions to No Access ...

If the disk in question is your Mac OS X startup disk and your computer stops starting up at the blue screen, restart with the Command and S keys held down, and enter the following commands:


mount -uw /

chown root /

chmod 1775 /

exit


https://discussions.apple.com/docs/DOC-2240

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Question marked as Best reply

Jul 21, 2012 5:10 PM in response to Ange101

Hello Angel,


See this User Tip by Niel: I accidentally set a disk's permissions to No Access ...

If the disk in question is your Mac OS X startup disk and your computer stops starting up at the blue screen, restart with the Command and S keys held down, and enter the following commands:


mount -uw /

chown root /

chmod 1775 /

exit


https://discussions.apple.com/docs/DOC-2240

Jul 23, 2012 2:44 AM in response to Ange101

Do you have an external disk and does it have a full backup?


Your cheapest solution is to purchase an external DVD drive - the cheap ones are about 10 UKP and you have a wide choice for a little extra. This would allow you to use Disk Utility on your install CD/DVD.


If your Mac has FireWire and you had an external FireWire hard disk you could install OS X on the external drive and boot from it. Via Target Disk Mode you could access your Mac's disk and back it up prior to doing a fresh install.

Jul 23, 2012 4:28 AM in response to Neville Hillyer

back it up prior to doing a fresh install.

A "fresh install," (or installing the OS on an external and booting via FW) which will lose all third party programs and cause a much bigger headache, is not necessary. I suggested an A&I. It is, of course, preferable to have a backup when doing this, but it will most likely come out alright.


Do you have an external disk and does it have a full backup?


If the OP had a "full backup," either in the form of a bootable clone or TM -- something I wouldn't ever think of not having -- then a restore from the date before this happened would take care of the problem. I assume there isn't one, since it probably would already have occcurred to the OP to do this.


This would allow you to use Disk Utility on your install CD/DVD.

I think the problem may be too severe for that. In most cases, whatever the OS, an A&I, reinstall, not erase and install (Snow Leopard) or restore is what is needed.




Message was edited by: WZZZ

Jul 23, 2012 4:31 AM in response to WZZZ

The OP has said the optical drive does not work so your archive and install is not quite as easy as you implied and I don't see how you think a backup can be done.


Booting an external drive and accessing the internal drive via FireWire will not destroy anything. This will allow Disk Utility to be used and also facilitate a full backup of the whole internal disk with Carbon Copy Cloner.

Jul 23, 2012 5:05 AM in response to Neville Hillyer

The OP has said the optical drive does not work so your archive and install is not quite as easy as you implied and I don't see how you think a backup can be done.

Missed that.


Booting an external drive and accessing the internal drive via FireWire will not destroy anything. This will allow Disk Utility to be used and also facilitate a full backup of the whole internal disk with Carbon Copy Cloner.

Disk Utility won't fix the Permissions. And a full backup right now will only clone/reproduce the Permissions problem. (But it will back up user and third party data.)


But running an A&I from another Mac in FW Target Disk Mode with the problem Mac as the target should work. This will basically turn the other Mac into an optical drive.


This thread, which is about doing a clean install -- not what we want -- gives the basic idea.


https://discussions.apple.com/thread/2317169



EDITED: Removed running the A&I from an external.


Message was edited by: WZZZ

Jul 23, 2012 6:33 AM in response to WZZZ

Booting an external drive and accessing the internal drive via FireWire will not destroy anything. This will allow Disk Utility to be used and also facilitate a full backup of the whole internal disk with Carbon Copy Cloner.

Maybe I'm misunderstanding something here, but the OP can not boot his Mac, the Permissions are completely hosed. How is he supposed to get OS X on an external in order to boot from that and use FWTDM, or download CCC and clone to that external? Even if he uses DU Restore -- and, anyway, a moot point, since with no optical drive I don't see how he gets to DU in the first place -- he will be copying hosed Permissions, and DU Permissions repair won't fix this.


As far as can tell, either he runs FWTDM from another PPC Mac to use its optical drive, or he borrows or buys an external optical drive.

Jul 23, 2012 11:14 AM in response to WZZZ

As I said earlier - with an external DVD drive and an external FireWire hard disk:

Your cheapest solution is to purchase an external DVD drive - the cheap ones are about 10 UKP and you have a wide choice for a little extra. This would allow you to use Disk Utility on your install CD/DVD.


If your Mac has FireWire and you had an external FireWire hard disk you could install OS X on the external drive and boot from it. Via Target Disk Mode you could access your Mac's disk and back it up prior to doing a fresh install.

Jul 23, 2012 11:58 AM in response to Neville Hillyer

This would allow you to use Disk Utility on your install CD/DVD.

What would the OP do with Disk Utility from the install DVD? Unless you mean use it to format the new external prior to installing an OS to it, what is that supposed to accomplish?


If the OP gets an external optical drive, why not then go straight to an A&I? What's the point of creating a backup of a completely hosed OS (which is what CCC or DU Restore would do) except perhaps to save user or third party data -- which an A&I should, by default, do? Certainly a backup/clone on an external to restore to in some future situation is desirable, but I don't see the point now. And why are you suggesting a fresh install, when an A&I from an external optical drive or from another Mac in Target Disk Mode is possible and preferable?


And, even if it were useful in some way, I wonder if it would even be possible -- I'm not sure of this -- to access the Mac's startup disk to do a backup, given its present condition?

Drive permissions to no access for everyone

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