Nenhuma das respostas anteriores mencionam bootcd , que parece corresponder exatamente à sua pergunta. No entanto, eu nunca tentei isso.
Esta é a descrição do pacote:
Build an image of your running Debian System with the command bootcdwrite. You can also build a bootcd ISO image via NFS on a remote System. When you run your system from CD you do not need any disks. All changes will be done in ram. To reuse this changes at next boot time you can save them on FLOPPY with the command bootcdflopcp. If booting from your CD-drive is not supported, booting from FLOPPY is possible. It is possible to install a new system from the running CD with the command bootcd2disk. Bootcd2disk can also find a target disk, format it and make it bootable automatically. Bootcd also supports lilo, grub, initrd, udev, lvm, transparent-compression ISO 9660 fs and syslinux/isolinux. The included FAQ describes how bootcd can do online or offline backups of other Linux distributions, resulting in restore-bootcds. The bootcdbackupwizard helps to create online backups.