Flashing globe

[zoran]

When booting my iMac, there is an earth globe flashing on and off and the iMac cannot boot. What does this flashing globe mean?

 

[jbarley]

Flashing globe" at Mac OS X startup and its meaning

 

[zoran]

The article says that "If this icon appears, it means that the system is attempting to NetBoot (startup from a remote volume), is failing doing so, and for some reason is not automatically moving to your valid Mac OS X installation"
but why in the first place does it attempt to make a NetBoot?

 

[jbarley]

Usually because the system cannot locate a bootable volume on the computer.
Now would be a good time to restore your system from a known good bootable backup.

 

[zoran]

Usually because the system cannot locate a bootable volume on the computer.
Now would be a good time to restore your system from a known good bootable backup.

Restore? Why do you say that?
I have a TMachine Backup, is that what you mean?

 

[Slartibart]

Restart your iMac and hold down the option (alt)-key. You will get an icon display of all available boot devices. Maybe even the internal volume does work but accidentally NetBoot was activated.

 

[zoran]

Is there some way to activate NetBoot on purpose? Maybe I pressed something?

But I still don’t get why #jbarley prompted for a Restore!

 

[Slartibart]

Is there some way to activate NetBoot on purpose? Maybe I pressed something?

that would be via the startup volume settings in the system preferences.

 

[zoran]

that would be via the startup volume settings in the system preferences.

If that’s the only way, then it could be some kind of malfunction. But do you have a comment on the Restore solution?

 

[Slartibart]

If that’s the only way, then it could be some kind of malfunction. But do you have a comment on the Restore solution?

he probably refers to restoring your system installation if you are unable to boot from the internal drive.

 

[zoran]

he probably refers to restoring your system installation if you are unable to boot from the internal drive.

Can I do that using my TimeMachine backup?

 

[Slartibart]

Can I do that using my TimeMachine backup?

of course.

 

[zoran]

So I don’t need to take any xtra measures, just to update my backup is enough... correct?

 

[Slartibart]

So I don’t need to take any xtra measures, just to update my backup is enough... correct?

You have to boot the Mac from the internal drive - maybe install/recover MacOS first or start it from an external medium - and then you can reinstall your user data from Time Machine

 

[jbarley]

So I don’t need to take any xtra measures, just to update my backup is enough... correct?

the normal method would be....
Start up while pressing the "Alt" key to get to the selection screen.
Select your Time Machine for start up.
Now select a backup to restore, preferably one from a time before your boot problem occurred.

 

[zoran]

Why select a backup prior to the problem?

 

[Slartibart]

Why select a backup prior to the problem?

Because you are sure that everything was working then, aren’t you? ?

 

[zoran]

But if I act like so with TMachine, that would mean, that I accept the problem is a software one and not hardware. Might that be true by taking in mind the fact that the iMac went to a NetBoot?

 

[Slartibart]

But if I act like so with TMachine, that would mean, that I accept the problem is a software one and not hardware. Might that be true by taking in mind the fact that the iMac went to a NetBoot?

If you are able to boot the machine from an external or the internal drive you can easily use the Diskutility to check the health of the internal drive. the reason that the machine tries to start via NetBoot might be related to a accidental change of the start volume.

The time machine backup is just the easiest way to return to your last known working software configuratio. if Diskutility reports problems you will have to address that.