3.2 RAM Disk or Persistent Storage Boot

There are two basic types of ttylinux installation, resulting in two type of booted systems: a RAM disk or persistent storage.

A Ram Disk installation results in a system that puts the root file system into RAM when it boots, which is what the bootable CD-ROM does. If you want to put ttylinux onto a flash drive, pen drive, USB memory stick, travel drive, etc. then you very probably want this sort of installation. This is typical for flash drives, but not for spinning hard disks, for at least two reasons: 1) flash drives have been much slower than hard drives, so maintaining a live file system on a flash drive has been intolerably slow, and 2) these are removable drive which have been difficult to consistently mount as they move between interfaces and computers. With this booting scheme, the boot loader takes the root file system from the drive and gives it to the kernel which decompresses it and mounts it as a read/write root file system in a RAM disk in memory. Changes to files in the root file system are lost when the system shuts down; persistent changes must be stored elsewhere. However, ttylinux has specific support for persistent changes to its boot-time startup with a RAM disk system, this is described section 3.3.5. The program /sbin/ttylinux-flash can be used to copy ttylinux from the CD-ROM to another drive and configure it to boot in this manner. The processes of putting ttylinux onto a drive for booting a RAM disk system and configuring its boot-time startup support is described in more detail in the next section 3.3.

A Persistent Storage installation results in a system that boots with the read/write root file system maintained directly on the spinning hard disk or solid state drive. If you have a spinning hard disk or one of the new fast solid state drives, and it is not removable, then you probably want this sort of installation. If you want to install onto removable media and will move the media to different slots or computers, then you do not want this kind of installation. The program /sbin/ttylinux-installer can be used to install ttylinux from the CD-ROM onto a spinning hard disk or solid state drive and configure it to boot in this manner. The processes of installing ttylinux onto a hard drive and booting a persistent storage root file system is described in more detail in section 3.4.