Translations:Initramfs/Guide/19/en

An initramfs is an initial ram file system based on tmpfs (a size-flexible, in-memory lightweight file system), which also didn't use a separate block device (so no caching was done and all overhead mentioned earlier disappears). Just like the initrd, it contains the tools and scripts needed to mount the file systems before the  binary on the real root file system is called. These tools can be decryption abstraction layers (for encrypted file systems), logical volume managers, software raid, bluetooth driver based file system loaders, etc.