This is with docker-ce=5:28.2.2-1~debian.11~bullseye, sysbox=0.6.7.linux on a Ubuntu 24.04 box, although I also confirmed it with sysbox 0.7.0.linux. This works: ``` $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=12345:12345 ubuntu:latest cat /proc/1/limits Max open files 12345 12345 files $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=200000:524280 ubuntu:latest cat /proc/1/limits Max open files 200000 524280 files ``` This doesn't work: ``` $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=524288:524288 ubuntu:latest cat /proc/1/limits Max open files 1024 524288 files $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=524289:524289 ubuntu:latest cat /proc/1/limits Max open files 1024 524288 files $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=12345:524289 ubuntu:latest cat /proc/1/limits Max open files 1024 524288 files $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=12346:524288 ubuntu:latest cat /proc/1/limits Max open files 1024 524288 files $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=524280:524288 ubuntu:latest cat /proc/1/limits Max open files 1024 524288 files $ docker run --runtime=sysbox-runc --rm -it --ulimit nofile=200000:524288 ubuntu:latest cat /proc/1/limits Max open files 1024 524288 files ``` By comparison, running without sysbox applies the limit as expected: ``` $ docker run --rm -it --ulimit nofile=524280:524280 ubuntu:latest cat /proc/1/limits Max open files 524280 524280 files ``` I can't find any reason why this would happen, and I looked through the sysbox source code, but that's the behavior I see on this machine.