Ubuntu 18.04 supports LZ4 Initramfs compression algorithm for reducing Boot time

The upcoming Ubuntu 18.04 LTS (Bionic Beaver) provides a more powerful compression algorithm for initializing the virtual memory disk, thereby further reducing the user’s boot speed. In previous versions of Ubuntu, the initramfs (initial ramdisk) phase mainly used the gzip compression algorithm. Canonical’s Balint Reczey announced today that the new version of Ubuntu will deploy LZ4 compression algorithms to provide faster compression and compression ratios without loss of data.

Reczey’s preliminary test results on older laptops showed that the initramfs extraction time dropped from 1.2 seconds to 0.24 seconds. The creation time of initramfs is also increased by 2-3 seconds, even if processing larger initramfs files can reduce the time by about 24-21 seconds.

Although Ubuntu 18.04 LTS (Bionic Beaver) is the first Ubuntu version to bring LZ4 compression to the initramfs, it is not activated by default, so the user needs to activate it manually. Canonical plans to activate by default in Ubuntu 18.10, released in October 2018.