Ubuntu 14.04 LTS works fine on a fusion drive. However, make sure you partition the drive using the installer and do not use the Mac version of the Ubuntu ISO. The regular version supports EFI booting which also negates the need for rEFInd. By installing in EFI mode, Ubuntu will be available as a boot option by holding down the Option key on.
We have a Late 2012 iMac in the shop that needs the 3TB hard drive replaced. Turns out this model has a Fusion drive with an SSD that is on the backside of the logic board.The drive has been swapped (new WD Blue 3TB), but we are having issues getting the Fusion setup, and getting OS Sierra loaded. I have tried researching the Fusion drive and what needs to be done, but all I can find is people trying to replace the HDD with an SSD, and other 'projects'.When we go to Disk Utility from a Sierra flash drive, it does not give me any options to rebuild the Fusion drive or anything like that.
If I plug up the original HDD to another Mac, it does tell me it needs to rebuild it, so that confirms it is a Fusion drive.How do we properly replace the HDD, and either get the system booting as-is (is the OS on the SSD?), or reload OS Sierra on it? We are currently working on doing a TimeMachine backup on the system, but it is about 2.2TB of data. A Fusion Drive is a composite of two physical drives: a fast but small SSD and a slower but larger HDD. Each of the physical drives contains three partitions: an EFI partition, a so-called physical volume and a special volume. The special volume on the HDD usually is the Recovery HD.The two physical volumes are part of a Logical Volume Group. Creating a default Fusion Drive means building one Logical Volume in the LVG spanning both physical volumes. The Logical Volume is the one mounted to root (and if enabled - the volume visible on the desktop).A file stored on the Logical Volume may reside on the SSD as well as on the HDD.
System files may also reside on both drives. Usually an algorithm ensures that system files are stored on the faster SSD but there is no guarantee.Removing one of the physical drives means removing one of the physical volumes and therefore tearing the LVG as well as the LV apart.
After destroying the LVG/LV the file system as well as system files or other files are corrupted and the remnants won't be bootable.To replace either of the drives, backup your exisiting volume(s) first with Time Machine. Then check whether you can boot to Internet Recovery Mode or create a bootable thumb drive and also try to boot to it.Shutdown your Mac and replace one (or both) of the old drives. Then boot to Internet Recovery Mode or the bootable thumb drive. Open Disk Utility and completely erase both disks (each to one volume/GPT/Journaled HFS and assign names e.g. 'fusion1' and 'fusion2' but not 'Macintosh HD').
Don't erase your thumb drive or a drive visible called Boot OS X. Open Terminal in the menubar Utilities Terminal and get the device identifiers of the two hard drives by entering diskutil list. Booted to Internet Recovery Mode you will get a list of 14-16 drives - only two of them are your hard drives. Simply check the sizes.
I'm really flummoxed.Earlier I was able to successfully get my system up and running by installing macOS onto my m.2 ssd while leaving my second ssd alone.I decided that I wanted to merge my two ssd together, so I erased my boot drive and went through the steps to fuse the two. It seemed to go off without a hitch because when finished, I started the installation process and was able to select my newly created 'fused' drive for my install location.It then went through the install process like the first time I was successful. The thing that was weird though is that when I got back into clover after the mid-install restart, I saw my USB installer and then two identical drives that said something to the effect of 'Boot install from macOS'. I went ahead and picked one of the two and as far as I could tell there was nothing to indicate any differences between the two drives. I did not see the 'Preboot' option this time. Anyway, the installation process continued.
I seemingly made it to the end. Then the computer restarted.Now the only options I see in BIOS when selecting my boot drives are my two hard drives (neither of them labeled as UEFI) and my USB installer. Before, when I had a working version, my boot drive was labeled with UEFI, and selecting it would boot me into macOS. That is no longer there. So either my system isn't seeing it or the installation didn't finish correctly like I presumed. Now the only bootable drive with a UEFI tag is the USB installer but unlike before, now when I select my installer to get into clover, all it does is hang at the 'Scan Entries' screen.I'm not sure what I did wrong but something isn't right anymore.
What I don't get is that it was working fine before the installation process completed but now I can't access anything. I'm wondering if I completely screwed myself over or if this is salvageable.
Is there just some setting that I need to change using Clover Configurator? Despite the fact that I haven't made any changes to my USB Installer/EFI folder is it possible that I need to reinstall Clover Bootloader?When I googled this and found some people suggesting that I make sure I have ApfsDriverLoader.efi or HFSPlus.efi in my drivers64UEFI/ folder, which both are. I'd assume I only need APFS since I installed Mojave?Any help you could provide would be much appreciated.
You need to manually copy a working /EFI/CLOVER/ and /EFI/BOOT/ directory to the EFI partition of either one of your fused drives. Clover installer and MultiBeast are unable to find the EFI partitions when launched from a fusion drive.See my latest post here:A UEFI motherboard shows a drive as bootable if it finds a file named BOOTX64.efi in the /EFI/BOOT/ folder of the EFI partition. I do not think it matters into which of the two EFI partitions you place the boot files, as long as the BIOS sees it.
I used the hard drive, as my older motherboard is unable to boot from NVMe directly.Tip: The easiest way to deal with multiple EFI / FAT32 partitions is to boot into Linux live.