LM 20 on 2011 iMac (intel)

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juicer
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LM 20 on 2011 iMac (intel)

Post by juicer »

Long story, short. iMac became unusable. Would crash on occasion, updated Mac OS to High Sierra but no better, crashed again and then more frequently until won't boot at all. Boot starts but fails before complete. Gray screen. Won't boot from external HD or into recovery mode. Used Apple's hardware check and both drives test OK. Online mention of failing AMD Rdeon gpu but since there is no onboard graphics, I am stuck if that turns out to be the issue. Cost prohibitive to replace and teardown/oven bake the gpu beyond my interest.
Am able to run from LM Mint 20 Live CD without issue so I thought I'd try to install LM.
SSD 250GB boot drive 2TB storage drive
Was able to use Apple's Target mode via firewire linking to another Mac to move important pics and docs off both drives.
Read where some partition the storage drive and install LM on that partition, leaving the Mac OS boot SSD drive alone and use the native Option/alt key at startup to select the boot option.
OK, so that was the short version.
Using Mac Target mode, I partitioned off 300 GB as ext 4 from the 2 TB storage drive and attempted to install.
Choosing "something else" in the setup, my inexperience shows.
I create / for the entire 300 GB but can't get beyond that.
I get an error "The partition table format in use on your disks normally requires you to create a separate partition for boot loader code. This partition should be marked for use as “Reserved BIOS boot area” and should be at least 1 MB in size. Note that this is not the same as a partition mounted on /boot.
If you do not go back to the partitioning menu and correct this error, bootloader installation may fail later, although it may still be possible to install the boot loader to a partition"
In the past, on machines intended for only Linux and only 1 drive, I have always used the "erase disk" option and never dealt with manual partitioning.
Not trying to complicate my request for help but just to better understand options, if I do use the "erase disk" selection, would I be offered the option to select the SSD or the storage HDD? If so, that might eliminate my uneducated fumbling.
Last edited by LockBot on Wed Dec 28, 2022 7:16 am, edited 1 time in total.
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majpooper
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Re: LM 20 on 2011 iMac (intel)

Post by majpooper »

I will let the real experts help you out here if the 300G on the HDD is really the way you want to go.
I have installed Mint on a few Macs. Full Disclosure: I am a kindergarten level linux person - so keep that in mind.
Anyway I would install Mint on the SSD (assuming it really is not jacked up) not the HHD (assuming it is a platter not an SSD) it will perform a lot better on the SSD. Also I would choose erase and use the whole disk (anyway that's what I did). If you are asked where to put the grub boot loader - put it on the SSD - probably sda

Now wait for somebody who knows what they are talking about to answer.
juicer
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Re: LM 20 on 2011 iMac (intel)

Post by juicer »

Agree on the benefit of the SSD. The reason I was sacrificing the HDD first was to see if the install in fact worked. Trying to partition it was a way of potentially testing without jumping in with 2 feet. Having now tried that I see it may be near impossible to reclaim that 300 GB partition. Men plan, the gods laugh.
On this iMac, the HDD is more easily accessible if I have to tear it down. The SDD is buried behind the motherboard with more cables and connectors to muck up along the way.
Macs may be sleek but they are a pain to disembowel.
Water invented man as a means of transportation.
Reddog1
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Re: LM 20 on 2011 iMac (intel)

Post by Reddog1 »

Your installer wants you to make a small Fat32 partition at the beginning of your drive on which to install the bootloader. Howerver, Ubuntu's Ubiquity installer would not install to that partition, anyway. Ubiquity installs to the first bootable efi partition it finds, and, from your description, that would be Apple's efi partition on the SSD (which is almost certainly seen by GParted as 'sda1'. The disk you are installing to is probably sdb. Even if you tell the installer to use the partition you made on sdb, it would still put the bootloader on sda (it's a bug). Apple doesn't have a bios, so there is no way to choose which hard drive that you boot from, other than the 'option' key at power up. I've never installed on an Apple with two separate drives, so I have to guess--but you might be able to boot live and use GParted to flag the the sda efi partition as not bootable, and then set the sdb partition as bootable and specify that the bootloader be installed on sdb, and maybe Ubiquity will find it--I just don't know.The other option is to make the partition and ignore it, and have the installer put the bootloader on the sda SSD. That should work, unless something happens to the ssd, then you can't boot. You really have nothing to lose, so you can try both.
But, I think installing Mint is the least of your problems. From your description of what is happening, I'm leaning towards a hardware and not software problem (not necessarily a HD problem). A bad power supply will do that--random crashes, boot fails, bad installs, etc., and it can seemingly be just random, due to failing over at certain loads.
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