"It worked quite well, but I can't really see the meaning on running two [RISC] OSes." Updates? For many years I do an update dance with NetBSD kernels. Two

"It worked quite well, but I can't really see the meaning on running two [RISC] OSes." Updates? For many years I do an update dance with NetBSD kernels. Two kernels with embedded filesystems on same bootable media, one updated, one not. Select kernel at boot, download appropriate userland to RAM disk then chroot. Download new kernel source, compile, repeat.