Finnix is the original utility live Linux distribution. Write it to a USB flash drive or burn it to a CD, boot it, and you're seconds from a root prompt with hundreds of utilities available for recovery, maintenance, testing and more.
Finnix is a Debian-based Live CD operating system, developed by Ryan Finnie and intended for system administrators for tasks such as filesystem recovery, network monitoring and OS installation. Finnix is a relatively small distribution, with an ISO download size of approximately 100 MiB, and is available for the x86 and PowerPC architectures, and paravirtualized (User Mode Linux and Xen) systems. Finnix can be run off a bootable CD, a USB flash drive, a hard drive, or network boot (PXE).
Finnix is released as a small bootable CD ISO. A user can download the ISO, burn the image to CD, and boot into a text mode Linux environment. Finnix requires at least 32 MiB RAM to run properly, but can use more if present. Most hardware devices are detected and dealt with automatically, such as hard drives, network cards and USB devices. A user can modify files nearly anywhere on the running CD via a union mount filesystem (UnionFS or AUFS, depending on the Finnix release), stacking a read-write filesystem (in this case, a dynamic ramdisk) on top of a read-only filesystem (the CD media). Any changes made during the Finnix session are transparently written to RAM and discarded upon shutdown. In addition, Finnix uses SquashFS to keep distribution size low.
Finnix can be run completely within RAM, provided the system has at least 192 MiB RAM available. If a "toram" option is passed to Finnix, most of the contents of the CD are copied to a RAM disk, and the CD is ejected, freeing the CD-ROM drive for other purposes. Finnix can also be placed on a bootable USB thumb drive, or installed permanently on a hard drive (though still functioning as if it were a LiveCD).
