Create a new VM with your settings. Port forward a local port, e.g. port 3022, to guest port 22. Mount the arch installation iso.
When at the promt, input:
systemctl start sshd
passwd
SSH in to the livedisk though the port you have forwarded:
ssh -p 3022 root@localhost
When you are in open gdisk
gdisk /dev/sda
And create the following partitions (for GPT and GRUB)
Number Start (sector) End (sector) Size Code Name
1 2048 6143 2.0 MiB EF02 BIOS boot partition
2 6144 518143 250.0 MiB 8300 Linux filesystem
3 518144 4712447 2.0 GiB 8200 Linux swap
4 4712448 268435422 125.8 GiB 8300 Linux filesystem
Create filesystems and mount them:
mkfs.ext4 /dev/sda2
mkfs.ext4 /dev/sda4
mkswap /dev/sda3
swapon /dev/sda3
mount /dev/sda4 /mnt
mkdir /mnt/boot
mount /dev/sda2 /mnt/boot
Install the base packages
pacstrap /mnt base
genfstab -p /mnt >> /mnt/etc/fstab