"Root device is read only"-?

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Level 1

7 points

"Root device is read only"-?

Hi!

I want to test my RAM using Memtest and start the Mac in Single user mode. But at the bottom of a long text, it says
"Singleuser boot -- fsck not done
Root device is mounted read-only"
What does this mean, and how can I change it?
OS 10.6.4

Kind regards - Hening.

MacBook Pro 2 GHz; Mac Pro 2.66 GHz Quad Core Intel Xeon, Mac OS X (10.6.4), OS 10.6.x on the MacBook Pro

Posted on Aug 21, 2010 8:40 AM

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Answer 1

Best reply

William-Boyd-Jr

Level 6

10,578 points

Aug 21, 2010 10:41 AM in response to hening

hening wrote:
"Singleuser boot -- fsck not done
Root device is mounted read-only"

A single-user boot always results in a read-only mount of the boot drive.

What does this mean, and how can I change it?

See this Web page:

http://www.westwind.com/reference/os-x/commandline/single-user.html

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Answer 2

baltwo

Level 9

62,362 points

Aug 21, 2010 10:48 AM in response to hening

AFAIK, there's no benefit running the test in single-user mode. Just download Rember and run it.

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Answer 3

hening Author

Level 1

7 points

Aug 22, 2010 5:59 AM in response to William-Boyd-Jr

baltwo,

AFAIK, there's no benefit running the test in single-user mode. Just download Rember and run it.

Well the text displayed in the shell during the execution says that multi-user mode may be less reliable and complete. In my case, only 5 of 6 GB of RAM were tested.

So I tried to run memtest in Single User mode. The prompt looks like this:

:/root #
and I type the path to the memtest folder which in turn contains the memtest tool; dates is the name of the volume, hening is my Home folder, bin is a folder in which I store bins:
cd volumes/dates/hening/bin/memtest ENTER
and get
"no such file or directory"
What am I typing wrong?

I wanted to try "~" for home folder, but can not find the tilde when in the command line interface. When I am in "normal mode", choose the US keyboard layout and open the Keyboard Viewer, it tells me that the tilde maps to "shift-<"-" on mine, and that worked. The keyboard I am using is a wireless keyboard with german Windows layout.

By the way, when I want to start in Single User Mode, I have to use the (wired) Apple keyboard; the cmd-s combination does not work in the intended way on my wireless one. However, once I am in the shell, the Apple keyboard strangely does NOT work any more, whereas the wireless one does.

Kind regards - Hening.

Message was edited by: hening

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Answer 4

hening Author

Level 1

7 points

Aug 22, 2010 6:07 AM in response to hening

The last-but-one paragraph in my last post contains garbage, which I could not change by editing. I try again:

I wanted to try "~" for home folder, but can not find the tilde when in the command line interface. When I am in "normal mode", choose the US keyboard layout and open the Keyboard Viewer, it tells me that the tilde maps to "shift-<"-" on mine, and that worked. The keyboard I am using is a wireless keyboard with german Windows layout.

--this is the same garbage! I try typing rather than pasting:

I wanted to try "~" for home folder, but can not find the tilde when in in the command line interface. When I am in "normal mode", choose the US keyboard layout and open the Keyboard Viewer, it tells me that the tilde maps to "shift-<" on my keyboard, but it does not. I used the same method to find out that "/" on the US keyboard maps to "-" on mine, and that worked. - The keyboard I am using is a wireless keyboard with German Windows layout.

Kind regards - Hening.

Message was edited by: hening

Message was edited by: hening

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Answer 5

Aug 22, 2010 8:46 AM in response to hening

hening wrote:
and I type the path to the memtest folder which in turn contains the memtest tool; dates is the name of the volume, hening is my Home folder, bin is a folder in which I store bins:
cd volumes/dates/hening/bin/memtest ENTER
and get
"no such file or directory"

I see two things wrong with that path: (1) It should have a slash before "volumes". (2) There should be a level of "Users" after "dates".

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Answer 6

hening Author

Level 1

7 points

Aug 23, 2010 10:30 AM in response to William-Boyd-Jr

Thank you for your reply.
I am the only user on my computer and have the Home folder on a volume different from the start volume, so the Users folder is on the latter. So the path should not need the Users level.
The slash I have added, but to no avail.
??
Kind regards - Hening.

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Answer 7

Aug 23, 2010 12:35 PM in response to hening

hening wrote:
I am the only user on my computer and have the Home folder on a volume different from the start volume, so the Users folder is on the latter. So the path should not need the Users level.
The slash I have added, but to no avail.

Try navigating one level at a time:

cd /Volumes
cd dates
cd hening
cd bin
ls

This should show you the point where your path navigation fails.

When you finally reach the bin directory and you see the memtest executable file, you should execute it with this command:

./memtest

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Answer 8

hening Author

Level 1

7 points

Aug 23, 2010 3:32 PM in response to William-Boyd-Jr

It finds Volumes, but Dates returns the "no such...". So it is because the Dates volume is different from the system volume. Is there a workaround for this?

Kind regards - Hening.

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Answer 9

Aug 23, 2010 6:17 PM in response to hening

hening wrote:
It finds Volumes, but Dates returns the "no such...". So it is because the Dates volume is different from the system volume.

As I supposed you controlled the "Dates" volume, I thought you knew what was on it. Is that not the case?

First, is the volume name "Dates" or "dates"? Case can matter on the command line. Second, after you execute the command "cd /Volumes", type "ls". Do you see anything resembling "dates" or "Dates"?

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Answer 10

hening Author

Level 1

7 points

Aug 24, 2010 2:54 AM in response to William-Boyd-Jr

As I supposed you controlled the "Dates" volume, I thought you knew what was on it. Is that not the case?

Oh yes it is. And Disk Utility shows Volumes/Dates (with caps) as the mount point. -

cd /Volumes returns
:volumes root#
then, ls returns a correct list of the volumes:
BOOTCAMP, Dates, Scratch, SnowL (startup), SnowL_Backup.
Then, cd /Volumes/Dates returns
:Dates root#
then, cd /Volumes/Dates/Hening (or hening) returns "no such...".

When I exit, I have to do it twice (except on one occasion). When the Shell shut down, I caught a glimpse of the last text, which said "unmount of Home failed".

Kind regards - Hening.

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Answer 11

Aug 24, 2010 8:53 AM in response to hening

hening wrote:
Then, cd /Volumes/Dates returns
:Dates root#

As you descend into a directory level, you don't need to repeat the hierarchy in the next "cd" command. So that last "cd" command could have been "cd Dates".

then, cd /Volumes/Dates/Hening (or hening) returns "no such...".

When you're positioned at the "Dates" level, what does an "ls" command show you?

When I exit, I have to do it twice (except on one occasion). When the Shell shut down, I caught a glimpse of the last text, which said "unmount of Home failed".

I'm not sure how to interpret either of those observations.

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Answer 12

hening Author

Level 1

7 points

Aug 24, 2010 11:56 AM in response to William-Boyd-Jr

the ls command at Dates level returns:
.autodiskmounted
:Dates root#

kind regards - Hening

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Answer 13

Aug 24, 2010 2:45 PM in response to hening

hening wrote:
the ls command at Dates level returns:
.autodiskmounted

Then you have no "hening" or "Hening" directory in the Dates volume.

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Answer 14

hening Author

Level 1

7 points

Aug 24, 2010 8:05 PM in response to William-Boyd-Jr

Oh yes I do! 🙂
I took a screen shot, but it looks like the forum does not allow upload of files. I pasted the jpeg in here, just to try. no, it does not show.
Kind regards - Hening

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Answer 15

Aug 24, 2010 9:15 PM in response to hening

hening wrote:
Oh yes I do! 🙂

Then why can't "ls" see it?

I took a screen shot, but it looks like the forum does not allow upload of files. I pasted the jpeg in here, just to try. no, it does not show.

Post the JPEG file elsewhere, then post the URL of that file in a message here.

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