This step requires mounting the QCOW2 image as a block device using NBD (Network Block Device), formatting it (ext4), and copying the extracted Cisco filesystem onto it.
losetup -fP cisco_disk.raw # map loop device mkfs.ext4 /dev/loop0p1 mkdir /mnt/cisco mount /dev/loop0p1 /mnt/cisco
This reduces the file size on your host machine while automatically decompressing files on-the-fly as the virtual machine reads data. Importing the QCOW2 Image into Virtual Labs
: Use QEMU to boot a temporary instance, pointing to your .bin file as the kernel/boot image and the new .qcow2 file as the primary drive. convert cisco bin to qcow2
For older legacy routers (e.g., 7200, 3725), you don't convert them to . Instead, you use them as-is within the cisco .bin images
: If you are looking for pre-built legal images, Cisco Modeling Labs (CML) provides nodes already in .qcow2 format, bypassing the need for manual conversion. Important Note
Once you have isolated the raw virtual disk image (let's assume it is named vios-image.img or input_disk.raw ), use the powerful qemu-img utility to convert it into a highly optimized QCOW2 image. Run the following command: This step requires mounting the QCOW2 image as
Network simulation platforms like GNS3, EVE-NG, and Cisco Modeling Labs (CML) have revolutionized how engineers design, test, and troubleshoot networks. However, to build realistic topologies, you need the right virtual disk images.
Create a properly named directory under /opt/unetlab/addons/qemu/ . (e.g., mkdir /opt/unetlab/addons/qemu/csr1000vng-16.12.05/ ). Upload your cisco_ios_xe.qcow2 file to this directory.
image files—the native firmware for physical routers—into the For older legacy routers (e
Optionally, you can optimize the QCOW2 file using QEMU's qemu-img command:
Upload your .qcow2 file to this directory using an SFTP client (like FileZilla).
tar -xvf image.bin
There are two primary scenarios when dealing with Cisco virtual images: converting a raw IOS/IOS-XE image or packaging a Cisco virtual appliance (like an ASAv or CSR1000v) that was provided as a raw binary.
Fix: Ensure your Linux user belongs to the kvm and libvirt groups, or prefix your initialization commands with sudo .