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Dead Hard Drive from Fusion Drive, how to always ignore?  



HI guys, I heard Dave mention that he had an iMac with a split fusion drive where the spinning drive was dead but he was still using the SSD portion of the drive solo. I have 2 iMac that have the same problem so I did the same thing and separated the Fusion drive and installed the system on the SSD. BUT, I get a warning after some time being logged in that a drive couldn't be mounted would I like to initialize, ignore or eject. I click ignore, but I have to do this every time the Mac is restarted. How do you deal with this Dave? Also, I had a Sierra installer but can't get High Sierra anywhere:-( I'll have to upgrade to Mojave, which I'm not too thrilled to do on this machine (iMac late 2012).

ok, found it

Normally this tool is used to prevent a disk from mounting, being written to, useful when running disk forensics on a dying disk. It will do the job for you.

On the said GitHub page, scroll down to the downloads link where you will find a releases link.

Hope it helps.

Hey Alex, checked your Disk Arbitrator, unfortunately, since there is no Volume created on this disk, it can't block it. I guess this is good if you have a working drive. Still have to check the other option with the command line. I did find a command line but everything I try happens AFTER whatever my mac is doing to try to spin it. I guess I'll wait for Dave to find a way to deal with it 😉 .

3 Answers

If you have ever installed High Sierra on any machine you've owned, you still should find it available for download in your Mac App Store Purchased items. 

Regarding your damaged drive, if you're not going to have the spinning drive replaced or removed, I vaguely recall or suspect there's a command line instruction to label the physical Disk ID to be ignored or disabled (?) I'm not sure on that.


First, the High Sierra Installer is still available at the Mac App Store... we always save these links. 😉

Second, @jefflambert670, you're absolutely right about my scenario. That's on the iMac in the Studio where we record. And, yep, I have to hit "Eject" after booting the machine. At some point I just need to pop that drive out of there. 😉

Thanks for the link to the installer. Thing is, I did install High Sierra on MY mac, but this was a company computer and I did't want it to be linked to my Apple ID, I thought I had downloaded it with the company's Apple ID but no, so Anyway it's running Mojave now. 


I was wondering if this problem was ever figured out? I too have an iMac where the main drive is dead and I have a bootable external drive on it but it keeps rebooting trying to start the internal drive back up. I have found no solution to prevent that (short of opening it up and disconnecting it, a lot of work) including "Disk Arbitrator".  Anybody?