imac will now default boot to external drive?

[grwren]

Hi. I have a late 2009 27" which I've been playing around with & booting to an external usb drive with Linux. It now default boots the external usb drive if left plugged in at startup, no Option key required! Is that normal or is it a potential problem?
Thanks.

 

[jerwin]

Fom this apple suport document
https://support.apple.com/en-us/HT202796

Press and hold the Option (Alt) key immediately after turning on or restarting your Mac.

1. Release the Option key when you see the Startup Manager window.
2. Select your startup disk, then click the arrow under its icon, or press Return.
   If you press and hold the Control key during this step, your selection is saved in Startup Disk preferences, so it persists until you change it.

two ways to fix it-- startup disk preferences, and in startup manager,selecting your macos volume with the control key pressed.

 

[Fishrrman]

This could also happen if your internal drive failed or otherwise became corrupted.
Have you tried booting from it lately?

 

[grwren]

Fom this apple suport document
https://support.apple.com/en-us/HT202796

two ways to fix it-- startup disk preferences, and in startup manager,selecting your macos volume with the control key pressed.

Thanks for reminding me of using the Control key, that should speed up selecting the start up drive.

 

[grwren]

This could also happen if your internal drive failed or otherwise became corrupted.
Have you tried booting from it lately?

As far as I can tell now the drive seems to be just fine (SMART says it's OK) and I boot to the macos frequently so that seems to be fine as well. It's just with the ext. drive plugged in I have to press the Option key and select the mac hdd from the boot manager or or with the ext. drive unplugged it will boot straight to the mac hdd. I'm going to be doing some testing with a few other Linux live boot usb's so I'll be monitoring it closely! Thanks for the reply.

 

[grwren]

Well, for what it's worth (& for who ever's interested) here's what I've discovered so far. Apparently for some reason my imac has discovered at least two methods of booting to the ext. usb Linux drive:

1. Method #1 - Normal (first ensuring everything is working right, i.e., the mac hdd is the preferred start drive, etc.):
Using the Option key at startup and selecting the UEFI drive symbol causes the imac to boot to the external Linux drive as expected> It will also boot as expected to Linux live boot usb drives or to the macos.

2. Method #2 - Other:
Apparently just leaving the usb cable attached at startup causes my imac to boot directly to the external drive. But, if I hold the Option key at startup I can choose the mac hdd and it seems to boot to the macos just fine. However, and this is where it gets odd: the external drive will no longer boot nor will the live boot drives.

At this point, to get everything back to normal, I reboot the mac, re-select the mac hdd as the startup drive and everything seems to return to normal. And so far nothing seems the worse for wear. My basic concern/question is:
Could Method #2 be causing some future boot problem or is the damage already done & it just hasn't appeared yet? Or am I worrying about nothing?

Hopefully some one can answer this question for me, any thoughts appreciated in advance!