gentoo grub # mv device.map device.map.old2
gentoo grub # grub-mkdevicemap
gentoo grub # cat device.map
(hd0)	/dev/disk/by-id/ata-VBOX_HARDDISK_VB1e6ac44f-a18d2f15
(hd1)	/dev/disk/by-id/ata-VBOX_HARDDISK_VBa4e17069-205f0312
gentoo grub # grub-mkconfig -o /boot/grub/grub.cfg
Generating grub.cfg ...
/sbin/grub-probe: error: no such disk.
gentoo grub #

[ebuild   R   *] sys-boot/grub-1.99_rc1