sysctl is used to modify kernel parameters at runtime. The parameters available
are those listed under /proc/sys/. Procfs is required for
sysctl support in Linux. You can use
sysctl to both read and write sysctl data.
The name of a key to read from. An example is kernel.ostype. The /
separator is also accepted in place of a ..
variable=value
To set a key, use the form
variable=value where
variable is the key and
value is the value to set it to. If the value contains quotes or characters
which are parsed by the shell, you may need to enclose the value in double
quotes. This requires the
-w parameter to use.
-n, --values
Use this option to disable printing of the key name when printing values.
-e, --ignore
Use this option to ignore errors about unknown keys.
-N, --names
Use this option to only print the names. It may be useful with shells that
have programmable completion.
-q, --quiet
Use this option to not display the values set to stdout.
-w, --write
Use this option when you want to change a sysctl setting.
-p[FILE], --load[=FILE]
Load in sysctl settings from the file specified or /etc/sysctl.conf if none
given. Specifying - as filename means reading data from standard input.
Using this option will mean arguments to
sysctl are files, which are read in order they are specified. The file argument can
may be specified as reqular expression.
-a, --all
Display all values currently available.
--deprecated
Include deprecated parameters to
--all values listing.
-b, --binary
Print value without new line.
--system
Load settings from all system configuration files.
/run/sysctl.d/*.conf
/etc/sysctl.d/*.conf
/usr/local/lib/sysctl.d/*.conf
/usr/lib/sysctl.d/*.conf
/lib/sysctl.d/*.conf
/etc/sysctl.conf
--patternpattern
Only apply settings that match
pattern. The
pattern uses extended regular expression syntax.
The
base_reachable_time and
retrans_time are deprecated. The sysctl command does not allow changing values of there
parameters. Users who insist to use deprecated kernel interfaces should values
to /proc file system by other means. For example: