Is it possible to boot an iMac from a USB the way you boot a Unix system?
I tried but it insists in _installing_ the system, not booting. I am trying to "see" the hard disk in a system that won't boot by itself, but I am trying to avoid reinstalling to make sure everything is as "untouched" as possible.
Thanks in advance.
(8 year old Intel iMac, I already have the startup USB ready)
iMac 27″
Alberto_FSoto wrote:
Is it possible to boot an iMac from a USB the way you boot a Unix system?
Yes it is possible to startup from a compatible macOS version on an external drive.
see > Change your Mac startup disk - Apple Support
What external USB drive do you have?
Does the iMac startup in macOS Recovery?
I tried but it insists in _installing_ the system, not booting. I am trying to "see" the hard disk in a system that won't boot by itself,
What happens when you startup the iMac?
see > If your Mac doesn't start up all the way - Apple Support
Have you tried Safe Mode to get the iMac working again?
see > How to use safe mode on your Mac - Apple Support
but I am trying to avoid reinstalling to make sure everything is as "untouched" as possible.
Have you tried reinstalling the macOS over the current version using macOS Recovery?
see > How to reinstall macOS - Apple Support
Reinstalling macOS over the top, does not wipe the user data like a full erase and reinstall. Besides you have a Time Machine or other backup to fall back on right...?
Alberto_FSoto wrote:
Is it possible to boot an iMac from a USB the way you boot a Unix system?
Yes it is possible to startup from a compatible macOS version on an external drive.
see > Change your Mac startup disk - Apple Support
What external USB drive do you have?
Does the iMac startup in macOS Recovery?
I tried but it insists in _installing_ the system, not booting. I am trying to "see" the hard disk in a system that won't boot by itself,
What happens when you startup the iMac?
see > If your Mac doesn't start up all the way - Apple Support
Have you tried Safe Mode to get the iMac working again?
see > How to use safe mode on your Mac - Apple Support
but I am trying to avoid reinstalling to make sure everything is as "untouched" as possible.
Have you tried reinstalling the macOS over the current version using macOS Recovery?
see > How to reinstall macOS - Apple Support
Reinstalling macOS over the top, does not wipe the user data like a full erase and reinstall. Besides you have a Time Machine or other backup to fall back on right...?
Thanks a lot for your answer and all the tips.
Trying to answer your questions. My iMac died over the weekend. I found a black screen with the "no parking" symbol on it, apparently some OS trouble. I have a current Time Machine backup, BUT there were some files I was working on (Office Word) that were not saved for a while (my bad, I know!). As far as I can see Time Machine keeps the last _saved_ version, but it does not keep the cached security versions that Word could use for auto-recovery. That is why I am trying to avoid reinstalling or rebuilding from the backup, as I am attempting to keep the hard drive as "untouched" as possible.
The iMac has a "Fusion Drive" made of a small SSD drive and a large HD. This could be part of the problem (more below).
Oh, and in case I need to specify: I am an absolute ignorant on this, I´m just trying to find all the info I can gather and play it safe. So I may be doing or assuming something obviously wrong, appologies if that´s the case.
Reinstalling macOS looks like the way to go, but I did not feel safe that it does indeed ignore the user data completely. If I could open it I would just take the HD out and reinstall everything, unfortunately that is not a practical option!
Once again thanks for your kind help. I´ll check the links you sent
Cheers,
A
Hey Dialabrain thanks for the note. I have Monterey 12.6.5 running from a Ravpower SSD, and using as main drive for a 2017 iMac. Have seen some flickers on the iMac monitor, nothing major but am concerned if it goes bad. What's needed to use the SSD with another monitor? Would like to go 21"+
rrrrbar wrote:
Hey Dialabrain thanks for the note.
You're welcome but your question has nothing to do with this thread. I assume you mean what's needed if your Mac goes bad. What would be needed is a new or used Mac capable of running Monterey.
You're welcome.
If you can not see the HDD in macOS Recovery, then it has failed and anything that was not previously backed up, is going to be very difficult and expensive to retrieve.
Difficult and expensive, as in having the HDD removed and sent out to a professional data recovery service.
My advise at this point, is to take the iMac into you local Apple Store or AASP and have it evaluated. Then decide on a repair or replacement and restore from the most current backup that you have.
To boot from an external drive you would need a drive that has macOS installed on it, not a bootable installer.
Thank you. I apologize for posting in a thread that had nothing to do with my question. I hope you have a nice day
You're welcome.
Thank you very much for your answer. I´d need instructions on how to get there, though---I will read the rest of the thread, maybe it´s already there. And I´ll check the web for that too.
Cheers,
A
Booting iMac from USB
