I was encouraged to share my experience with installing macOS Big Sur on two of my cMPs as I wasn't able to find anything already prescribed for those like me who use the RefindPlus/OpenCore Chainloader, and hopefully it covers off some useful information for others attempting the same. I have also included installing the Mojave Security Update 2020-007, which I did first.
Systems
Mac Pro 2009 4,1>5,1 – dual 6-Core 3.33GHz – 64GB Ram (my secondary cMP only has 48GB Ram)
Sapphire Pulse RX590 8GB (my secondary cMP has a Sapphire Pulse RX580 8GB)
BootRom 144.0.0.0.0
WiFi 802.11ac/BT 4.0 Combo card - BCM94360CD
Both of my systems are pretty much identical - both have macOS Mojave on NVMe blades (PCIe single adapter), plus other SSDs in PCIe SATA III adapters and SSDs in the SATA II bays, along with other HDDs for Time Machines plus bootable High Sierra and Mojave backups of my primary drives (using CCC). My primary cMP has Windows 10 Pro (Legacy) solely on its own SSD in SATA II bay.
RefindPlus/OpenCore Chainloader
Both of my systems have RefindPlus/OpenCore Chainloader v0.6.4a installed. I can't speak highly enough of how fantastic it is.
The only mod I have made to the base
My normal boot/startup sequence is as follows:
I power on or restart and it boots to RefindPlus. I then select the primary OpenCore (
Security Update 2020-007
System Update was prompting me about the Mojave Security Update 2020-007 as well as upgrading to macOS Big Sur.
1. So I backed up my data with TimeMachine (TM) and made another backup copy of my boot drive and User data drive using CCC (Carbon Copy Cloner).
2. I then clicked to install Mojave Security Update 2020-007.
3. Halfway through the update it restarted, and that then takes me to the RefindPlus screen, so I selected my primary OpenCore instance.
4. At the OpenCore pick list it already had the Install Update drive selected (an * to the left of it indicating it was the set boot drive), so I pressed Enter/Return and it completed the Security Update.
5. My system then rebooted back to RefindPlus, I then selected my primary OpenCore and selected my Mojave boot drive.
My cMP then completed the update and presented the login screen.
Installing macOS Big Sur
Booted into Mojave I could see System Update prompting me to upgrade to macOS Big Sur.
1. I clicked on the option in System Update to upgrade to macOS Big Sur. The file was approx 12.22GB (version 16.1.04). This put the Install macOS Big Sur installer in my /Applications folder, and it automatically started the installer upon download completion.
2. I wanted to install Big Sur on a SSD (Samsung 860 EVO 500GB) in one of the SATA II bays (Direct Connect Bay). In my primary cMP, it was a brand new SSD so I just formatted it as APFS GUID. On my secondary cMP that already had Catalina installed, I decided to add Big Sur in addition to Catalina (not upgrade Catalina to Big Sur) so I added another partition to that SSD in Disk Utility by selecting the Container of the SSD (in the left hand pane) and selecting the Partition icon, and chose the Add Volume option (not the Partition option).
3. Back to the Install macOS Big Sur installer, I selected the SSD I wanted to install to and it went about the install process.
4. There were three restarts as part of the full install. So each start takes me back to the RefindPlus screen, and where I select my primary OpenCore instance. At the OpenCore pick list it automatically had the Install macOS Big Sur installer preselected, so I just hit Enter/Return and it continued on with the install process. On the third restart I selected my Big Sur drive in the OpenCore picklist and it booted successfully into Big Sur. I had to then create a User account and work through the other initial setup choices.
Learnings
The process of installing Big Sur was absolutely straight forward using the primary
• I didn't have to use
• I didn't have to make changes to boot-args or do any other trickery in Terminal, or Recovery HD etc.
• I didn't have to create a USB installer or use any of the patchers or processes in the macOS 11 Big Sur on Unsupported Macs Thread.
So upgrading/installing Big Sur was actually much easier than even installing Catalina (where I had to use the
Will I upgrade my entire production system from Mojave to Big Sur? No, not yet at least. I was reluctant to upgrade and transfer everything to Catalina, so I'll just stick with Mojave for the time being. But I'll certainly be able to play around with Big Sur.
Feel free to ask any questions.
Systems
Mac Pro 2009 4,1>5,1 – dual 6-Core 3.33GHz – 64GB Ram (my secondary cMP only has 48GB Ram)
Sapphire Pulse RX590 8GB (my secondary cMP has a Sapphire Pulse RX580 8GB)
BootRom 144.0.0.0.0
WiFi 802.11ac/BT 4.0 Combo card - BCM94360CD
Both of my systems are pretty much identical - both have macOS Mojave on NVMe blades (PCIe single adapter), plus other SSDs in PCIe SATA III adapters and SSDs in the SATA II bays, along with other HDDs for Time Machines plus bootable High Sierra and Mojave backups of my primary drives (using CCC). My primary cMP has Windows 10 Pro (Legacy) solely on its own SSD in SATA II bay.
RefindPlus/OpenCore Chainloader
Both of my systems have RefindPlus/OpenCore Chainloader v0.6.4a installed. I can't speak highly enough of how fantastic it is.
The only mod I have made to the base
config.plist for both OC and OC_ALT are that Innie has been set to <true/> so that my PCIe SATA III SSDs and NVMe blades are shown as internal.My normal boot/startup sequence is as follows:
I power on or restart and it boots to RefindPlus. I then select the primary OpenCore (
OC) option (not the OC_ALT option which has VMM activated) and it chain loads to the OpenCore picklist. My primary boot OS is Mojave, and I have set this as my startup drive in System Peferences > Startup Drive, and so this tells OpenCore it's the primary boot drive and displays an "*" to the left of my primary boot drive to indicate it is default boot drive. So I can either press Enter/Return, or press the number to the left of my boot drive and it boots to my Mojave drive, or wait 30 seconds (option set with MyBootMgr - one of the RefindPlus utilities) and it automatically boots to my default boot drive.Security Update 2020-007
System Update was prompting me about the Mojave Security Update 2020-007 as well as upgrading to macOS Big Sur.
1. So I backed up my data with TimeMachine (TM) and made another backup copy of my boot drive and User data drive using CCC (Carbon Copy Cloner).
2. I then clicked to install Mojave Security Update 2020-007.
3. Halfway through the update it restarted, and that then takes me to the RefindPlus screen, so I selected my primary OpenCore instance.
4. At the OpenCore pick list it already had the Install Update drive selected (an * to the left of it indicating it was the set boot drive), so I pressed Enter/Return and it completed the Security Update.
5. My system then rebooted back to RefindPlus, I then selected my primary OpenCore and selected my Mojave boot drive.
My cMP then completed the update and presented the login screen.
Installing macOS Big Sur
Booted into Mojave I could see System Update prompting me to upgrade to macOS Big Sur.
1. I clicked on the option in System Update to upgrade to macOS Big Sur. The file was approx 12.22GB (version 16.1.04). This put the Install macOS Big Sur installer in my /Applications folder, and it automatically started the installer upon download completion.
2. I wanted to install Big Sur on a SSD (Samsung 860 EVO 500GB) in one of the SATA II bays (Direct Connect Bay). In my primary cMP, it was a brand new SSD so I just formatted it as APFS GUID. On my secondary cMP that already had Catalina installed, I decided to add Big Sur in addition to Catalina (not upgrade Catalina to Big Sur) so I added another partition to that SSD in Disk Utility by selecting the Container of the SSD (in the left hand pane) and selecting the Partition icon, and chose the Add Volume option (not the Partition option).
3. Back to the Install macOS Big Sur installer, I selected the SSD I wanted to install to and it went about the install process.
4. There were three restarts as part of the full install. So each start takes me back to the RefindPlus screen, and where I select my primary OpenCore instance. At the OpenCore pick list it automatically had the Install macOS Big Sur installer preselected, so I just hit Enter/Return and it continued on with the install process. On the third restart I selected my Big Sur drive in the OpenCore picklist and it booted successfully into Big Sur. I had to then create a User account and work through the other initial setup choices.
Learnings
The process of installing Big Sur was absolutely straight forward using the primary
OC option from RefindPlus.• I didn't have to use
OC_ALT (with VMM activated).• I didn't have to make changes to boot-args or do any other trickery in Terminal, or Recovery HD etc.
• I didn't have to create a USB installer or use any of the patchers or processes in the macOS 11 Big Sur on Unsupported Macs Thread.
So upgrading/installing Big Sur was actually much easier than even installing Catalina (where I had to use the
OC_ALT option that has VMM activated).Will I upgrade my entire production system from Mojave to Big Sur? No, not yet at least. I was reluctant to upgrade and transfer everything to Catalina, so I'll just stick with Mojave for the time being. But I'll certainly be able to play around with Big Sur.
Feel free to ask any questions.
