who can give some advice on the options presented during partitioning?
Trying to install Manjaro alongside MacOS on a 2011 iMac – creating a new partition on the HD for Manjaro – I have come to a point where I need some help.
Using the graphical Manjaro installer, I chose to manually partition the HD, to create one additional partition for Manjaro.
So far, so good. At this point now there’s a step in which I am asked to choose a „mount point” and a „flag” (and a name) for this new partition. Without this, the process won’t go on.
What is convenient or compulsory to choose/check in that dialogue?
In the Wiki and in multiple pages read, including these forum support pages, I was unable to find an answer to this specific question, and I don’t want to rely on trial and error, in order not to wreck anything.
Given that it’s a Mac and that you still have macOS on it, there should already be two partitions on the drive, being an EFI system partition and a macOS partition. So neither of those have to be touched.
Manjaro needs at least one partition for itself, but if you have less than 16 GiB of RAM, then it is advised to create a swap dfevice. This swap device can be a dedicated swap partition, or a swap file on the Manjaro root filesystem. The recommended size for the swap device is at least the size of your RAM, and if you plan on using suspend-to-disk, then better is to choose twice the size of your RAM.
The mountpoint for the root filesystem must always be “/” — it does not require a flag — and you will probably also want to set up the /boot/efi mountpoint for the EFI partition.
However, because this a Mac, it is possible that the EFI system partition is formatted with hfsplus, which is not writable to GNU/Linux.
Therefore, I recommend that you would create an additional partition of about 300 MiB, formatted as vfat (FAT32), and that you set this partition up with the mountpoint /boot/efi, and with the boot or esp flag — the installer will treat them as being the same flag, but they are actually separate and distinct flags.
So the EFI partition is formatted in FAT32.
Furthermore it has „no mount point”.
It is flagged „boot”.
Partitions sda2 (MacHD) and sda3 (MacOS Recovery) both have „no mount point” and no flags.
All this according to the Manjaro GUI installer.
Swap: If, at the beginning of the installation process, I choose „erase disk and install Manjaro”, the installer offers the option of creating a swap section (4 ways). If I choose „manual partitioning” there is no such option to be seen, at least not at that stage.
Memory: its size is 14 GB.
So what would be the recommended procedure for the new Manjaro partition, after having downsized the MacOS partition, and: is there anything to be done about the EFI partition?
This planned Manjaro installation is not intended for eternity. In the long run I will erase the disk or replace it with an SSD and make a fresh Manjaro install, like I did with my own 2011 iMac. The one I am fiddling around with here is my wife’s.
Well, as said earlier, the Manjaro partition should have “/” as its mountpoint, and does not require any flags. The EFI partition should be given the /boot/efi mountpoint.
With 14 GiB of RAM, and given that you don’t intend to make this a permanent installation, you can go without a swap partition, but then do bear in mind that you won’t be able to suspend-to-disk. Whether that’s an issue or not depends on your personal preferences — personally I never suspend my machine, but that’s just me. You can either way always create a swap file later if you change your mind.
They will be mounted automatically when trying to access them, but only in read-only mode, given that Linux cannot write to hfsplus.
Unfortunately I get an error message. But first things first:
I did what you recommended:
EFI partition:
had no mount point; was given mount point /boot/efi
Furthermore (we didn’t mention this):
EFI partition had flag „boot”; that was left unchanged.
EFI partition had only 200 MB; was upsized to 400 MB. (Initially, I had overlooked this minimum size requirement of 300 MB, and I got an error message: „EFI partition not correctly configured. In order to configure an EFI system partition, go back and choose or create an appropriate file system. Size: 300 MB min. You may go on without, but your system might not start.”
Now, the EFI partition being the first one on the disk (sda1), I had to free space, which I could only take from sda2 (MacHD). Anyway, I had to downsize sda2 in order to create space for the newly-to-be-created Manjaro partition.
So I cut a little bit on the left and a big portion – about half – on the right, upsized sda1 and created a partition for Manjaro. I practised it several times, but the persisting error message is:
I would opt to not resize the EFI partition; Yes, calamares will nag if it’s less than 300 MiB, but it shouldn’t really be a problem. So you do not need to move your macOS partition.
Apple’s Disk Utility did the partitioning at the second attempt.
After that, installation via „Replace a partition” (instead of manual partitioning, of course) was a matter of minutes.
There were no questions or warnings whatsoever. Which very probably means that the original EFI partition was not modified in any way: size 200 MB, no mount point (?).
I might come back on some theoretical questions later.
I wanted the Manjaro GUI installer to make space and create a new partition on the HDD of a 2011 iMac (3rd install option: manual partitioning), shrinking the MacOS partition and enlargening the EFI partition from 200 MB to 300 MB (or more), hence pushing the MacOC partition slightly to allow more space for EFI.
It failed at this resizing task several times, and I had to fall back on „Disk Utility”, the Macintosh tool, to do the partitioning job. Then I was able to install Manjaro via option 1 („replace a partition with Manjaro”).
But this way, the EFI partition was not modified. Neither was it enlargened nor was it probably given the /boot/efi mountpoint that was recommended (honestly, I don’t yet understand these terms).
1st question:
What would have been improved if the EFI partition had actually been modified? – Since it wasn’t modified: could anything happen?
2nd question:
During the manual partitioning procedure, the installer suggested creating a swap partition or file. During the „replace-one-partition” procedure there was no such prompt.
As long as I don’t miss a swap section (I have never missed one, didn’t know until yesterday what it was), I think I will be fine. But if I should miss one in the future, I suppose I will have to use another tool to create one – some disk utility for Linux, won’t I?
The mountpoint is only a directory in the running system onto which the partition will be mounted, so that it would be accessible to the running system. Therefore, the mountpoint is assigned by the running system — it is not set in the partition table or in the partition header itself.
On account of the EFI system partition concretely, the mountpoint for it in Manjaro is /boot/efi — Fedora for instance mounts it at /efi — and thus, there must exist a directory /boot/efi for the partition to be mounted onto, as well as a line in /etc/fstab referencing the partition, the mountpoint, the filesystem type, and the mount options for said filesystem.
I have written a couple of elaborate tutorials regarding drives and partitions, and regarding file permissions, which I strongly recommend you read.
The EFI partition is a primitive filesystem — usually a FAT-derivative — containing so-called EFI stubs. An EFI stub is a small file in the EFI executable format, which, as an extension of the firmware (but created by the operating system upon installation), allows the EFI to boot the installed operating system. As such, it should be regarded as part of the EFI boot manager process.
The reason why the official recommendation is to make it at least 300 MiB is that Microsoft Windows tends to dump a lot of stuff in there, which would quickly lead to the EFI partition filling up, and especially so on systems with more than one version of Windows installed.
GNU/Linux doesn’t do that. This here below is the content of my own EFI partition, on a system with only Manjaro installed.
As a swap device, Linux — the kernel — prefers a dedicated partition, so that it can access the raw disk blocks. A swap partition is not mounted anywhere, but accessed by the kernel directly (based upon the information about it in /etc/fstab).
However, Linux can also use swap files, and although the creation and correct configuration of those is a little more complicated on btrfs, it is still possible to create swap files later if necessary without needing to repartition your drive. The swap file will then reside on your root filesystem instead.
So you don’t need to worry about that now, and there are excellent tutorials on how to do it if push ever comes to shove.
and allow me time to digest this and read the tutorials.
You may suspect from the way I ask questions that I have no more than some basic knowledge. I started with Linux about two years ago because I wanted to leave Apple behind, and I chose Manjaro because it suited me for a couple of specific reasons – features I found in M. that I missed elsewhere.
The forum is a great help when it comes to solving problems that arise along the way.
