sudo -s
for f in sys dev proc ; do mount --bind /$f /media/ssd/$f ; done
chroot /media/ssd
grub-install /dev/ssdsda
update-grub

# in fstab:
... ext4    discard,noatime,nodiratime,errors=remount-ro 0       1

tmpfs /tmp tmpfs defaults,noatime,mode=1777 0 0