GRUB boot Arch ISO, inside a hard disk

Requirements

If set to “auto”, the root file system image is copied to tmpfs if the root file system image is less than 4 GiB and the free RAM exceeds the root file system image size plus 2 GiB.

If you met the hard memory size limit, but ArchISO failed to do copytoram=y by default, copytoram=y is required.

Or you will kill yourself if you continues with the normal installation guide.

You must edit the secondary grub boot menu (after selecting the archiso boot entry) by pressing "E"

Then append `copytoram=y` to kernel parameters line, press "Ctrl+X" to boot.

Steps

Get and verify ISO.

curl -Lo /archlinux-x86_64.iso http://mirrors.tencentyun.com/archlinux/iso/latest/archlinux-x86_64.iso

Add this to the top of menuentries to make it the default menuentry.

/boot/grub/grub.cfg

menuentry '[loopback]archlinux-x86_64.iso' {
  set iso_path='/archlinux-x86_64.iso'
  export iso_path
  search --set=root --file "$iso_path"
  loopback loop "$iso_path"
  root=(loop)
  configfile /boot/grub/loopback.cfg
  loopback --delete loop
}

Reboot. Now you say you use arch btw.

/etc/pacman.d/mirrorlist

Server = http://mirrors.tencentyun.com/archlinux/$repo/os/$arch

Belows are configurations dumped from Tencent Cloud cloud-init package.

/etc/default/grub

GRUB_CMDLINE_LINUX_DEFAULT="splash=silent showopts crashkernel=-1M-3G:0M,3G-8G:192M,8G-16G:256M,16G-64G:384M,64G-128G:512M,128G-486G:768M,486G-972G:1024M,972G-:2048M net.ifnames=0 biosdevname=0 console=ttyS0,115200 console=tty0 panic=5 intel_idle.max_cstate=1 intel_pstate=disable processor.max_cstate=1 amd_iommu=on iommu=pt"