Recently I came across a user who requested an increase to the ulimit settings for nfsd kernel processes.
root 1122 0.0 0.0 0 0 ? S 11:43 0:00 [nfsd] # grep 'open file' /proc/1122/limits Max open files 1024 4096 files This appears to default to 1024/4096 soft/hard.
As you can see from the brackets surrounding nfsd, this is a kernel process spawned from kthreadd and thus won’t inherit limits from systemd (or limits.conf)