No Cd Rom Found Mikrotik Full - Fatal Error

The error originates in the RouterOS boot script /etc/rc.d/rc.sysinit (within the initrd). The installer checks for:

if [ ! -b /dev/cdrom ]; then
    echo "fatal error: no cd rom found"
    reboot
fi

It then tries to mount /dev/cdrom to /cdrom and look for the packages directory. If you have access to the boot console (e.g., via Ctrl+Alt+F2 during boot), you could manually create a symlink from your USB device to /dev/cdrom, but this is complex and not recommended.

If you must use the legacy ISO (e.g., for a specific old device), try these three fixes in order.

For 99% of users encountering the "fatal error no cd rom found mikrotik full" message, the correct path is to install CHR (Cloud Hosted Router) directly onto the hard drive. The CHR image is a raw disk image, not an ISO, so there is no CD-ROM check at all. fatal error no cd rom found mikrotik full

This means the ISO is corrupted or the USB creation tool failed. Redownload the ISO and use Rufus (DD mode) on Windows or dd on Linux.

When installing MikroTik’s RouterOS on a physical machine or a virtual environment, users may occasionally encounter the cryptic error: “fatal error no cd rom found”. At first glance, this message seems outdated—after all, modern servers and PCs rarely rely on physical CD-ROMs for operating system installation. However, the error persists as a legacy condition within the MikroTik installer, and understanding it requires a look at the software’s design philosophy and boot process.

If you are trying to install the "full" version, the official, error-proof method is Netinstall. This bypasses the CD-ROM requirement entirely. The error originates in the RouterOS boot script /etc/rc

What is Netinstall?
Netinstall is a utility (Windows/Linux) that boots MikroTik over the network (Ethernet) without any local media.

Steps:

Verdict: If you see the "fatal error" more than once, abandon ISO boot and switch to Netinstall. It is faster and more reliable for full installations. It then tries to mount /dev/cdrom to /cdrom

  • If you used passthrough for USB, try connecting the USB installer directly to the host and presenting it to the VM.

    • MikroTik RouterOS uses a Linux kernel, but the installation process is highly specialized. Unlike a standard Ubuntu or Windows installer that scans aggressively for any connected storage, the MikroTik installer (especially older ISO versions) often looks for a strictly defined "CD-ROM" device path.

    When you see "No CD-ROM Found," it typically means one of three things: