Raising the soft limit to the hard limit is also recommended by the author of systemd: https://0pointer.net/blog/file-descriptor-limits.html https://0pointer.ne

Raising the soft limit to the hard limit is also recommended by the author of systemd: https://0pointer.net/blog/file-descriptor-limits.html https://0pointer.net/blog/file-descriptor-limits.html I doubt the kernel would actually allocate the resource space upfront. Like SO_SNDBUF and SO_RCVBUF, it's probably only allocated when it's actually needed.