JBOD as boot for iM...
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JBOD as boot for iMac 2017?

New Member Customer


Complete newbie here (I had troubles with the security question!)

I joined to post and then realised this is actually a forum for a commercial software, so apologies for the hijack, but it looks like a good place for good advice!

My question:

I have made my own fusion drive on my current iMac: external 256GB SSD with the internal 1TB HD. It's worked groovy for the last 5 years. It's fast, and I enjoy the simplicity for backing, cloning and TimeMachine - 1 drive - 1 back up - 1 clone.

I'm upgrading to an iMac with an internal 256GB SSD, which isn't big enough for my needs. So I bought an external 1TB SSD. I'd like to keep the simplicity of my current set up, so am considering JBOD.

I'm aware of the added risks of failure of concatenated drives, but I think I'm covered by my back up strategy (between Time Machine, cloning and iCloud, I think I should be OK).

But can I use JBOD as a start up drive? is it stable?

Thanks for any insight


Topic starter Posted : 05/02/2019 3:40 am
Member Admin

Apple does not allow RAID startup volumes for Mojave. A concatenated volume might work on a non T2 machine, you have to test it. You probably need to use Carbon Copy Cloner or SuperDuper to move the System data to your volume, I doubt Mojave will install onto it.

Posted : 05/02/2019 12:22 pm
New Member Customer

So as my machine is not T2, it is in theory possible, although you have doubts I would actually be able to do it. Maybe not worth the hassle then.
Thanks for your answer.

Topic starter Posted : 06/02/2019 2:52 am
Member Admin

I would not, as another issue is no OS or Security update would be possible, either.

I have seen a user starting from a SoftRAID non RAID volume. But you cannot install onto to it, so it requires being cloned.

What would have to be your process is cloning a system to your volume, keeping a copy of your boot drive, then having to reclone, apply any OS X or Security update on the copy, and cloning back. And never being assured that the next update to OS X would not kill off your startup solution.

Until Apple "blesses" startup from non standard volumes, we are best to avoid trying.

Posted : 06/02/2019 12:47 pm