ERROR:'/dev/disk/by-label/arch-201901' device did not show up after 30 seconds Falling back to interactive prompt.You can try to fix the problem manually log out when you are finished.

blkid
#拔掉u盘，再次运行blkid，而可以看到label为arch-201901的，
mkdir /arch
mount /dev/sda1 /arch #blkid可以看到
##可以进入系统了