missing operating system, press any key to reboot

[*MiK]

I've repaired my osx volume with diskwarrior, now i'm not longer able to boot my osx (i get the error "missing operating system, press any key to reboot"); but the files of the partition are all there... it seems that the boot record was gone.

There is any way to rebuilt the osx boot record, without reinstall?

[hecker]

Yes, you can do that by booting of your DVD and typing the following:

sudo fdisk -u /dev/rdisk# (replacing rdisk# with the appropiate disc number)

 

If you do not know what your rdisk number is, try typing:

diskutil list

 

hecker

 

EDIT: Added sudo to the command

Edited March 16, 2007 by hecker

[*MiK]

Yes, you can do that by booting of your DVD and typing the following:

fdisk -u /dev/rdisk# (replacing rdisk# with the appropiate disc number)

 

If you do not know what your rdisk number is, try typing:

diskutil list

 

hecker

 

thanks for the reply..

 

i've tryed this in the terminal from the install dvd:

 

#fdisk -u /dev/rdisk0s2

 

 

but i still get the error

:[

[hecker]

i've tryed this in the terminal from the install dvd:

 

#fdisk -u /dev/rdisk0s2

That was almost corrrect. Replace rdisk0s2 by rdisk0, like this:

sudo fdisk -u /dev/rdisk0

 

If it still doesn't work then try finding out if your partition is set as "active" by doing the following:

sudo fdisk -e /dev/rdisk0
p (to view partitions)

 

The partition you need should be listed and marked as active with an asterisk next to it.

If it's not, then you can set the active partition by typing

 

f # (replace # with correct partition number)
write (answer yes to question)
exit

 

hecker

Edited March 16, 2007 by hecker

[*MiK]

That was almost corrrect. Replace rdisk0s2 by rdisk0, like this:

sudo fdisk -u /dev/rdisk0

 

If it still doesn't work then try finding out if your partition is set as "active" by doing the following:

sudo fdisk -e /dev/rdisk0
p (to view partitions)

 

The partition you need should be listed and marked as active with an asterisk next to it.

If it's not, then you can set the active partition by typing

 

f # (replace # with correct partition number)
write (answer yes to question)
exit

 

hecker

 

...it doesn't worked.

now when booting the hd light become red forever, but osx doesn't appears.

 

And if i try to make an "update" installation? Would this fix the mbr too?

[hecker]

Try booting with -v to see what error messages you are getting and post them here.

 

Did you check if the partition was active? Does the Darwin bootloader even show up?

 

hecker

[*MiK]

Try booting with -v to see what error messages you are getting and post them here.

 

Did you check if the partition was active? Does the Darwin bootloader even show up?

 

hecker

 

Darwin bootloader is gone... by pressing F8 nothing happens, only red hd light is on.

[hecker]

Mik, boot off your DVD again, run

diskutil list

and post what you see, here.

Then run

fdisk -e /dev/rdisk0
p

and post what you see, here.

 

I think you still have not correctly created the MBR.

Why exactly did you have to use diskwarrior to "fix" your drive?

 

hecker

[*MiK]

Mik, boot off your DVD again, run

diskutil list

and post what you see, here.

Then run

fdisk -e /dev/rdisk0
p

and post what you see, here.

 

I think you still have not correctly created the MBR.

Why exactly did you have to use diskwarrior to "fix" your drive?

 

hecker

 

i've posted a screenshot; i've used diskwarrior because the osx diskutil was unable to fix an error on disk; by using vmware i can see all files on the osx partition; so it must be only a boot record error

[hecker]

The screenshot seems ok.

Do you have any idea what the error was that diskwarrior had to fix?

I'm really out of ideas, sorry. But I would personally save the data and repartition the whole drive.

 

hecker

 

EDIT: I had this link in my documents. Maybe it could help you:

http://docs.info.apple.com/article.html?artnum=106214

Edited March 16, 2007 by hecker

[*MiK]

The screenshot seems ok.

Do you have any idea what the error was that diskwarrior had to fix?

I'm really out of ideas, sorry. But I would personally save the data and repartition the whole drive.

 

hecker

 

EDIT: I had this link in my documents. Maybe it could help you:

http://docs.info.apple.com/article.html?artnum=106214

 

 

thanks for your replies.. seems that i have to reinstall ((

can i install osx over the partition without losing settings, programs, etc?

Edited March 16, 2007 by *MiK

[hecker]

can i install osx over the partition without losing settings, programs, etc?

No bro, not that I know.

But you could copy them over to another partition, if you have one.

 

hecker

[*MiK]

Osx back to life!

 

After searching a lot on google, i've come up to the solution: copy the first 512 bytes from another osx partition to the damaged one; then repair permissions to the partition;

[shmk]

Where do you find the first 512 bytes?