I've booted into the ventoy boot menu, had selected the holoiso and got this error message.
ERROR: '/dev/disk/by-label/HOLO_202207' device did not show up after 30 seconds
I didn't found anything in the official error list so I've removed the holo part and found this and ŧhis thread.
Long story short, I've entered the following commands.
mkdir /mnt_ventoy_data
mount /dev/sdb1 /mnt_ventoy_data
mkdir /mnt_iso
mount /mnt_ventoy_data/HoloIso_[...].iso /mnt_iso
ln -sf /mnt_iso /dev/archiso
exit
That's it. So what have I done in detail? With the knowledge that I was dropped into a ramfs and that the arch bootup script is expecting a /dev/archiso, all I need to do is to mount the right iso file.
To get this iso file, I first needed to mount the ventoy data partition. Once mounted, all I need to do is to mount the iso and softlink this mount to /dev/archiso.
Next and most important part, I had serious trouble get 3D and wifi working with my default installation. I could not find anything but I made it. And the reason why all is now working fine is simple "switch from linux-lts to linux".
So if you want to have a smooth 3D party and a working wifi, switch to latest arch linux kernel "5.19.1".