The conversation on this page has been archived and is no longer active.

Option to choose different start up disk?

Message #1 - Posted 2005/03/05 - Phil Stripling

I sometimes travel with an iBook and a small firewire drive. Just in case my iBook's install of OS X crashes in flames, I've installed OS X on the firewire drive. Am I correct in my recollection that holding down the option key as you power on the computer lets me choose the startup disk?

I'm thinking that's the only way to start up if the internal drive is kaput, OS-wise.

Phil Stripling | email to the replyto address is presumed The Civilized Explorer | spam and read later. email from this URL http://www.cieux.com/ | http://www.civex.com/ is read daily.

Message #2 - Posted 2005/03/06 - Zaphod B

Phil Stripling wrote:

I sometimes travel with an iBook and a small firewire drive. Just in case my iBook's install of OS X crashes in flames, I've installed OS X on the firewire drive. Am I correct in my recollection that holding down the option key as you power on the computer lets me choose the startup disk?

Yes.

I'm thinking that's the only way to start up if the internal drive is kaput, OS-wise.

It could also happen that it will find the alternate OS by itself; probably depends on just how kaput the main system (or disk) is. The worse the hit it took, the greater is probably the chance that the Mac won't even try to boot from it, and go to the secondary instead. It might whir abbout a bit first though, so give it maybe thirty seconds to a minute before you decide it hasn't found anything.

Alternatively, boot by using a bootable CD/DVD (e.g., your own Restore or Install disc), in that case you hold down the 'C' Key. --
/Z

Message #3 - Posted 2005/03/05 - Phil Stripling

NOT.diskworld@mac.com.INVALID (Zaphod B) writes:

won't even try to boot from it, and go to the secondary instead. It might whir abbout a bit first though, so give it maybe thirty seconds to a minute before you decide it hasn't found anything.

Do I understand correctly that if it isn't finding the OS after I powerup, I can hold the option key down after it's whirred awhile and have it do the dialogue on what disk to look on? That would be nice.

Phil Stripling | email to the replyto address is presumed The Civilized Explorer | spam and read later. email from this URL http://www.cieux.com/ | http://www.civex.com/ is read daily.

Message #4 - Posted 2005/03/06 - Ron Parsons

Previously, Phil Stripling wrote:

NOT.diskworld@mac.com.INVALID (Zaphod B) writes:

won't even try to boot from it, and go to the secondary instead. It might whir abbout a bit first though, so give it maybe thirty seconds to a minute before you decide it hasn't found anything.

Do I understand correctly that if it isn't finding the OS after I powerup, I can hold the option key down after it's whirred awhile and have it do the dialogue on what disk to look on? That would be nice.

No, if it doesn't find a working startup on the volume were it was expected, it may take some time searching for other possible systems to boot from. If it finds one, it will boot from it without you doing anything.

If you are unable to wait, hold the power button down until it shuts down completely then start it up again holding the Option key.

Before you head out on the trip, you might want to try using the startup with the Option key just to be sure that it will boot from the external.

Message #5 - Posted 2005/03/07 - Anno Siegel

Ron Parsons <jrp59@gte.net> wrote in comp.sys.mac.system:

Previously, Phil Stripling wrote:

NOT.diskworld@mac.com.INVALID (Zaphod B) writes:

won't even try to boot from it, and go to the secondary instead. It might whir abbout a bit first though, so give it maybe thirty seconds to a minute before you decide it hasn't found anything.

Do I understand correctly that if it isn't finding the OS after I powerup, I can hold the option key down after it's whirred awhile and have it do the dialogue on what disk to look on? That would be nice.

No, if it doesn't find a working startup on the volume were it was expected, it may take some time searching for other possible systems to boot from. If it finds one, it will boot from it without you doing anything.

If you are unable to wait, hold the power button down until it shuts down completely then start it up again holding the Option key.

Before you head out on the trip, you might want to try using the startup with the Option key just to be sure that it will boot from the external.

Alternatively, you can make the external drive the default boot disk (via System Preferences -> Startup Disk). If the external drive isn't connected, it will discover that fast (you'll see a question mark for a half-second) and boot from the internal drive. If the external drive is connected, it will boot from that. YMMV.

Anno

Message #6 - Posted 2005/03/07 - Simon Slavin

On 05/03/2005, Phil Stripling wrote in message <3qacphaaxp.fsf@shell4.tdl.com>:

Do I understand correctly that if it isn't finding the OS after I powerup, I can hold the option key down after it's whirred awhile and have it do the dialogue on what disk to look on? That would be nice.

Hold the option key down while powering-up. It will go into a mode where it scans everything looking for possible boot-sources. Once it has found all its boot-sources it offers an additional option: rescan. So you can attach other drives, power them up, insert bootable DVDs, then hit the rescan button and it'll start checking all devices again.

Simon.

Using pre-release version of newsreader.
Please tell me if it does weird things.

Message #7 - Posted 2005/03/07 - Tom Stiller

Previously, Simon Slavin wrote:

On 05/03/2005, Phil Stripling wrote in message <3qacphaaxp.fsf@shell4.tdl.com>:

Do I understand correctly that if it isn't finding the OS after I powerup, I can hold the option key down after it's whirred awhile and have it do the dialogue on what disk to look on? That would be nice.

Hold the option key down while powering-up. It will go into a mode where it scans everything looking for possible boot-sources. Once it has found all its boot-sources it offers an additional option: rescan. So you can attach other drives, power them up, insert bootable DVDs, then hit the rescan button and it'll start checking all devices again.

I have never had rescan find a device that wasn't powered up before I (re)started the Mac.

Tom Stiller

PGP fingerprint = 5108 DDB2 9761 EDE5 E7E3
7BDA 71ED 6496 99C0 C7CF

Need Help? Have a Question?

Looking for more help, comments, and answers?

Ask your questions on Ask Different. Ask Different is a community of Apple users ready to help.