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RAID1 Catalina

New Member

Dear all,

I have a Mac-Mini 2012 with two x 2TB SSD

I would like to merge both SSDs into RAID1

I know that under RAID0 it is not possible to install Catalina on the startup disk

However I seem to have read somewhere that Catalina can be installed on a RAID1

If so how would I go doing that since in order to configure the Mac mini to a RAID1 with SoftRaid there must be Catalina already installed. But then when I try using SoftRaid to create the RAID1 SoftRaid tells me that I need to initialise the drives first which means that the SSDs would be formatted. Which to me sounds like an impossible task because if I initialise the SSDs I loose everything installed on those two SSDs. It is not the data that is an issue since I have a backup however it seems to me that although I understand that we cannot install macOS Catalina on the startup disk using RAID0 how can I achieve that if all I want is to set up a RAID1 with Catalina installed on the Mac mini.

I thought of cloning the primary SSD that is the start up disk with all my software, then I would have formatted both SSDs and then installed macOS Catalina and Softraid to create the RAID1 with SoftRaid. But again I am finding myself with the same issue that is that both SSDs need to be initialise first before creating a new volume.

Please if you can help I will be very grateful,

Many thanks and KR

Topic starter Posted : 28/05/2021 1:02 am
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I can tell you what to do, but it may not work, as Apple makes it very difficult to boot from RAID now.

First, you need SoftRAID 5.8.4, not 6.0, as we removed bootability from the driver in version 6.

Next you need an external drive. Install Catalina into it, or use Carbon Copy CLoner to clone your Mini boot volume to the external.

Run SoftRAID and create a RAID 1 volume.

Run CCC in reverse and clone your volume to the Mini RAID 1 volume.

Set startup in System Preferences. From the Set Startup preference pane, click "restart". If your system does not restart, but beeps instead, you won't be able to boot.

I would then just use Apple's RAID. You can convert your volume to Apple RAID using SoftRAID.

Then try setting the volume as the startup. Its possible you can startup using Apple's RAID.

Note: Catalina will over write the SoftRAID driver, and each Security update you will need to reinstall the SoftRAID driver.

Posted : 28/05/2021 1:25 am
New Member

If I remember correctly, you've also got the problem, that system updates won't install on a RAID volume.

You can use CCC to get almost the same functionality as a RAID-1 :

  • Set CCC to run every hour using the new "Quick Update"
  • Set "Find and replace corrupted files" to "Once a week"

Another alternative, is to partition the SSDs into System & Users. You can then do a RAID-1 on the Users and use CCC on a regular basis on the System partitions.

Posted : 04/06/2021 4:31 pm