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1. Install UTM and create a new VM with the Rocky iso. This loops in Grub due to the above restriction.
2. Stop the VM. Right-click on VM `VM Edit->QEMU` >QEMU and untick `untick Use Hypervisor` to enable emulation. In the same settings window, change `change Display->Emulated Display Card` from ` from virtio-gpu-pci` to ` to virtio-ramfb` otherwise there is not display output.
3. Boot and install OS as usual.

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1. First install some build dependencies as root: 

   Code Block
   language bash theme Eclipse
   dnf -y groupinstall 'C Development Tools and Libraries' dnf -y groupinstall 'Development Tools' dnf -y install ncurses-devel openssl-devel elfutils-libelf-devel python3 dnf config-manager --set-enabled powertools dnf -y install dwarves wget

2. Grab a kernel and unpack: 

   Code Block
   language bash theme Eclipse
   wget https://mirrors.edge.kernel.org/pub/linux/kernel/v4.x/linux-4.18.tar.gz tar xf linux-4.18.tar.gz

3. Config kernel and use booted kernel config as a base
   

   Code Block
   language bash theme Eclipse
   cd linux-4.18/ make O=~/build/kernel mrproper cp /boot/config-`uname -r` ~/build/kernel/.config

4. Change kernel page size. With, e.g., make menuconfig search CONFIG_ARM64_64K_PAGES and change it to 4K .
   

   Code Block
   language bash theme Eclipse
   make O=~/build/kernel menuconfig sed -ri '/CONFIG_SYSTEM_TRUSTED_KEYS/s/=.+/=""/g' ~/build/kernel/.config grep PAGES ~/build/kernel/.config # sanity check

5. (optional) set target name
   

   Code Block
   language bash theme Eclipse
   vim Makefile # to change `EXTRAVERSION` kernel name suffix sed -i 's/^EXTRAVERSION.*/EXTRAVERSION = -4Kpages/' Makefile # alternative make O=~/build/kernel kernelversion # check kernel version target

6. Build the kernel (this takes a while due to emulation...)
   

   Code Block
   language bash theme Eclipse
   make -j 4 O=~/build/kernel make O=~/build/kernel modules_install

7. Install kernel
   

   Code Block
   language bash theme Eclipse
   cp ~/build/kernel/arch/arm64/boot/Image /boot/vmlinuz-4.18.0-4Kpages cp -v ~/build/kernel/System.map /boot/System.map-4.18.0-4Kpages kernel-install add 4.18.0-4Kpages /boot/vmlinuz-4.18.0-4Kpages

8. Reboot into the new kernel. If successful, shutdown the VM.

9. Re-enable the Use Hypervisor  option and change the Emulated Display Card  back to virtio-gpu-pci  to enable virtualization.

10. Refer to this guide for building Lustre MASTER with Rocky 8.7. Double check there is enough space available in the VM.

(Optional) Migrate VM from UTM to VMware Fusion Pro

VMware Fusion Pro does not support emulation and therefore the used Rocky image cannot boot without building a kernel with a compatible page size first. Moreover, even when migrating to VMware, the stock kernel is incompatible. So, it is important to first build the Lustre kernel.

Note, Oracle Linux 8.7 is the only flavor that can boot out of the box with VMware Fusion. Rocky/Alma/CentOS do not boot without a compatible kernel.

The following documents the steps for a successful migration:

1. Make sure to have build a Lustre kernel before continuing. (Other kernel configurations probably work too except the stock kernel).
2. In UTM first run dracut --force --no-hostonly  which rebuilds the initramfs with all drivers available. This is important to support the storage bus type in VMware. Later (when in VMware), dracut --force  rebuilds initramfs only with the needed drivers.
3. Shutdown the VM and convert the qcow2 VM file to vmdk via qemu-img . If command not available, install qemu (e.g., via brew: brew install qemu ). This command creates a new vmdk file, leaving qcow2 untouched.:

   Code Block
   language bash theme Eclipse
   # First, navigate to the UTM VM directory qemu-img convert -p -f qcow2 -O vmdk <VM_file_name>.utm/Data/*.qcow2 ~/Downloads/rocky8-7.vmdk

4. Add VM in VMware Fusion and use Create a custom virtual machine , choose Use an existing virtual disk .

5. Boot into the existing Lustre kernel.

6. Final steps:

   1. Fix swap: swapon /dev/mapper/rl-swap --fixpgsz 

   2. The NIC has changed, so the old config file no longer applies: Navigate to /etc/sysconfig/network-scripts/ , change the file name and the config, i.e., the NAME  and DEVICE  fields. 

   3. Set a new hostname

   4. Regenerate hostkeys cd /etc/ssh && rm ssh_host_* && ssh-keygen -A 

   5. (optional) nvme drivers on EL8 seem to be buggy regarding low power states. This results in an unresponsive machine for 30 seconds. syslog reports nvme nvme0: I/O 123 QID 2 timeout, aborting; nvme nvme0: Abort status: 0x0. This can be avoided by changing the disk interface to SATA in the VM disk settings.

7. Reboot and done.