Sysctl (command)

sysctl configure kernel parameters at runtime.

• https://man7.org/linux/man-pages/man8/sysctl.8.html

• sysctl -a, --all Display all values currently available.
• sysctl -p Load in sysctl settings.
• /etc/sysctl.d/
• /etc/sysctl.conf

• sysctl vm.swappiness

sysctl -w vm.nr_hugepages = 204832
sysctl -w vm.max_map_count=262144

KVM VNC remote viewer

iptables -t nat -A PREROUTING -i eno1 -p tcp --dport 5900 -j DNAT --to 127.0.0.1:5900
sysctl -w net.ipv4.ip_forward=1
sysctl -p /etc/sysctl.conf

• sysctl -w kernel.perf_event_paranoid=X (node exporter )

• sysctl -w net.ipv4.ip_forward=1
• sysctl -w net.ipv6.conf.all.forwarding=1

• sysctl -q net.ipv4.conf.all.src_valid_mark=1

• sysctl -w vm.max_map_count=262144

• macOS: sysctl machdep.cpu.features

• net.ipv4.tcp_mtu_probing (SSH2_MSG_KEX_ECDH_REPLY)

• sysctl -w fs.file-max=100000

• sysctl -w vm.nr_hugepages = 204832

Related terms

• Docker added support for sysctl options in docker services in docker (2019-07-22)
• Tunning
• sysctl fs.file-max
• K8s 1.21 (April 2021) added support for sysctl
• Redis values.yml: sysctl.enabled: false

See also

• sysctl, -a, -p, -w, vm.swappiness, /etc/sysctl.conf, /etc/sysctl.d/, net.ipv4.ip_forward, OOM, Kernel.shmmax, prlimit
• procps: Proc, sysctl, slabtop, /etc/timezone
• Process, zombie process, fork, thread: ps, tree, pstree, ps axf, proc, pwdx, which, watch, sar -q, tload, uptime, Interrupts, pgrep, tasklist (Windows), Zombie process, pstack, docker ps, docker-compose ps, jobs, acct, process mrelease, pidstat, IPC, pidof
• Linux Kernel: namespaces, Cgroups, OOM, proc, Linux Kernel changelog, sysctl, userfaultfd, Grub, ENOSPC, ENOMEM, DKMS, syscall, Transparent huge pages, smatch, sysfs, vm.swappiness, CFS, Runlevel, Jens Axboe, Consistent Network Device Naming, Initial ramdisk (initrd), modprobe, MTD, Linux Kernel vulnerabilities, /sys/kernel/, KernelCare, unix://, Data Plane Development Kit (DPDK)

https://github.com/prometheus/node_exporter

https://github.com/moby/moby/pull/37701