Glitch with bootable external drive o/s Yosamite

Question

Glitch with bootable external drive o/s Yosamite

I have old iMac model 7.1 (2007) with bootable 3 TB La Cie external drive which contains spare bootable volumes. One for Yosamite and one for Lion.

I formatted and tested the volumes originally several years ago. I keep them as I have the entire Adobe CS5 suite working in its original form. CS5 works best on Lion. The iMac itself has only a 320 GB drive and 4GB memory. Generally it is used for Microsoft Office.

Today I tried to start up from the external drive and found the iMac was unable to boot from the external drive. Most odd!

The external drive volumes are visible on the Yosamite desktop. I have verified the external volumes with disk utility and registered the startup disk to suit Lion volume. On past occasions I have had no problems.

If I close and start up holding down Option, the only visible volume is the iMac Yosamite. The external drive volumes do not register.

Can anyone suggest a possible fix.

Posted on Apr 2, 2022 7:19 PM

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Answer 1

Top-ranking reply

Australopithicus01 Author

Level 1

13 points

Apr 3, 2022 6:59 PM in response to my ginger

Many Thanks again My Ginger.

Unfortunately no other cable. Certainly I agree I should consider getting a spare but I would have assumed a connection glitch via cable or port would be either all on or all off.

I have looked at the link you supplied and it seems perfect to trial Terminal. A lot of bonus good information there also.

Many Thanks for that. I shall let you know how I go. I shall be away from the computer today so I shall keep you informed Tuesday.

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Answer 2

my ginger

Level 5

4,910 points

Apr 3, 2022 6:28 PM in response to Australopithicus01

Using terminal may or may not do it. Do you have another cable you can try out to connect the external drive?

http://www.robertopasini.com/index.php/2-uncategorised/556-osx-setting-the-startup-disk-using-terminal

You might be able to use a Lion installer to reinstall Lion. If the drive with Lion will show.

Mac OS X Lion Installer

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Answer 3

my ginger

Level 5

4,910 points

Apr 3, 2022 10:16 AM in response to Australopithicus01

From you internal drive with the external plugged in. Go to disk utilities and run repair on the external volumes. Not verify. Also would not hurt to run disk permissions on the external drive volumes if you can.

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Answer 4

Apr 3, 2022 4:32 PM in response to my ginger

Thank you for the response my ginger.

I have run Repair Disk on disk utilities and got 100% OK. Disk Permissions are 100% OK.

I have a Disk Warrior USB which confirms all volumes, host and external, at 100% efficiency.

If there is a reader who is good with Terminal I think disc selection via Unix instruction will answer the problem if a Unix guru can help please.

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Answer 5

Apr 4, 2022 5:02 PM in response to Australopithicus01

Hi My Ginger,

I could not get Terminal to run. Entered sudo bless etc. after which I was asked for password. Entered password hit return and the command line prompt re-appeared. I assume the password is the same as the Administrator password. If not - I have no idea what is required.

Moving on: tested external drives on the second iMac, same model, faster chip. Both worked well and could boot up in Lion.

So the older iMac (iMac 1) has an O/S system glitch. Am rebuilding fresh o/s from installer on iMac 2 using a clean volume. Will transfer the new O/S after installing account data, back to iMac1 using Target Disk mode after erasing iMac1 HDD. Clean install should fix the problem.

If not, iMac 1 may have a hardware fault. Not good enough. its only 15 years old!

Thank you for your help My Ginger.

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