LCTL-SET_PARAM(8)

NAME
lctl-set_param - Lustre filesystem set parameter utility

SYNOPSIS
lctl set_param [-n] [-P] [-d] <parametervalue...>
lctl set_param -F <filename>

DESCRIPTION
Set the value of the named Lustre or LNet parameter to value on the local node. Parameter names consist of one or more components, separated by a '.' (period). Each component may be specified by plain text or by a wildcard in the glob(7) format. When wildcards are used, more than one parameter may match and be changed. Parameters are often, but not always, of the form obd_name.obd_instance.parameter_name, where obd_name is one of the OBD object types, like ldlm, llite, lmv, lov, mdc, osc, etc., and obd_instance is the name of a Lustre device, like testfs-OST0000, but may be a specific component, or contain wildcards to match some or all devices on the node. Parameters can only be modified by the root user for security reasons.

-d  Remove the permanent setting (only for parameters set with the -P option).

-F  Set parameters from filename instead of from the command-line. The contents of filename is YAML format, created as an output from 'lctl --device MGS llog_print <fsname>-client' or any other valid llog configuration log as listed by 'lctl --device MGS llog_catlist'

-n  Disable printing of the parameter name after setting it.

-P  Set parameter permanently on all nodes connected to the MGS on which the command is run. To limit wildcard parameter matching to specific filesystems or parameters, ensure that parameter contains a suitably-specific expression for the obd_name and obd_instance, such as the filesystem and/or target name. This option is only available in Lustre 2.5.0 and later clients, older clients cannot set persistent parameters, nor will they see them.

EXAMPLES
# lctl set_param fail_loc=0 timeout=20
fail_loc=0
timeout=20
# lctl set_param -n fail_loc=0 timeout=20
0
20
# lctl set_param -P osc.testfs-OST*.max_dirty_mb=512
osc.testfs-OST0000-osc-ffff8803c9c0f000.max_dirty_mb=512
osc.testfs-OST0001-osc-ffff8803c9c0f000.max_dirty_mb=512
osc.testfs-OST0002-osc-ffff8803c9c0f000.max_dirty_mb=512
osc.testfs-OST0003-osc-ffff8803c9c0f000.max_dirty_mb=512
osc.testfs-OST0004-osc-ffff8803c9c0f000.max_dirty_mb=512

SEE ALSO
lustre(7), lctl(8), lctl-get_param(8), lctl-list_param(8), lctl-llog_catlist(8), lctl-llog_print(8)