Welcome to Devil-Linux
Devil-Linux is a distribution which boots and runs completely from CDROM or USB flash drive. The configuration can be saved to a floppy diskette or a USB pen drive. Devil Linux was originally intended to be a dedicated firewall/router but now Devil-Linux can also be used as a dedicated server for many applications. Attaching an optional hard drive is easy, and many network services are included in the distribution.
Because boot/OS and (optionally) configuration [in a tarball] are stored on read-only media, Devil-Linux offers high security with easy and safe upgrades, the system being fully configurable with no writeable system device. If hard drive(s) are added for data storage, LVM is standard (easing expansion and backup) and software Raid is straightforward. Virtual machine use is also well supported, with VMware modules built-in.