We noticed this issue today and there is a further aspect to it. I won't have time to make a proper bug report for a couple of days.
The initrd path that was given to the pxe netboot installer gets included in the boot command line, to wit: GRUB_CMDLINE_LINUX="initrd=::debian/stretch/amd64/debian-installer/amd64/initrd.gz" so we ended up with $ cat /proc/cmdline BOOT_IMAGE=/boot/vmlinuz-4.9.0-3-amd64 root=/dev/sdc1 ro quiet initrd=::debian/stretch/amd64/debian-installer/amd64/initrd.gz This was for a machine with no NVMe device, just an internal SSD. During installation the ssd was enumerated as /dev/sdc. After installation it gets enumerated as /dev/sda. The other /dev/sdX devices seem to be usb devices in the monitor, I've attached the hardware-summary. See also #865473, which may be related. Best wishes Vince
