While installing the image on SRX4600, using a USB drive, it gets stuck with the following warming: 

WARNING: Bogus /etc/fstab file - cannot have /dev/root as the device for /
init=/sbin/init
root=
rootflags=
rootfstype=
root_ro=0
root_rw=0
Adding product as SRX-SUMMIT   SRX4600   I2C
Installation on SRX4600
Install device is /dev/sda
Second device is
dd: failed to open '': No such file or directory
Bug in initramfs /init detected. Dropping to a shell. Good luck!
bash: cannot set terminal process group (-1): Inappropriate ioctl for device
bash: no job control in this shell

This can happen if the SSD1 Slot is empty.

While booting the Bios, it will try fetching the device information about the primary and backup SSDs. If it finds that the SSD1 slot is empty, then this warning message appears.

If SSD was removed from slot1 or if it was already empty, then insert it back in slot1 (at least insert the defective SSD itself in the empty slot).