added Linux version for sysctl

pages/linux/sysctl.md

@@ -0,0 +1,23 @@
+# sysctl
+
+> List and change kernel runtime variables.
+
+- Show all available variables and their values:
+
+`sysctl -a`
+
+- Set a changeable kernel state variable:
+
+`sysctl -w {{section.tunable}}={{value}}`
+
+- Get currently open file handlers:
+
+`sysctl fs.file-nr`
+
+- Get limit for simultaneous open files:
+
+`sysctl fs.file-max`
+
+- Apply changes from /etc/sysctl.conf:
+
+`sysctl -p`