A change proposal has been raised to compress the initrd by default using Zstd compression rather than XZ. This change would help provide some disk savings as well as speeding up the boot process on modern systems with Fedora Linux.
Dracut for generating the initial RAM disk “initrd” already uses Zstd by default when the zstd binary is found present on the system. But with the zstd program binary not being found by default on most Fedora Linux editions out-of-the-box, it means Dracut ends up falling back to using XZ compression.
This change proposal seeks to ensure that Zstd is used for compressing the initrd across all Fedora variants with Dracut. In turn this means space savings on the disk and potentially faster boot times.
Fedora CoreOS is among the variants that already are using Zstd for initrd by default. Benchmarks previously shown there have shown measurable boot time improvements.
The Fedora 43 change proposal still needs to be voted upon but as it’s a fairly straight-forward change of ensuring Zstd is installed, it will presumably be passed.
