1 .TH LCTL-GET_PARAM 8 "2019-06-17" Lustre "configuration utilities"
3 lctl-get_param \- retrieve configuration parameters
6 .IR "\fBlctl get_param " [ -F "] [" -n | -N "] [" -R "] <" parameter ...>
9 Get the value of the named Lustre or LNet
11 on the local node. Parameter names consist of one or more components,
12 separated by a '.' (period). Each component may be specified by plain text
13 or by a wildcard in the
15 format. When wildcards are used, more than one parameter may match and
16 be returned. Parameters are often, but not always, of the form
17 .IR obd_name.obd_instance.parameter_name ,
20 is one of the OBD object types, like
21 .BR ldlm ", " llite ", " lmv ", " lov ", " mdc ", " osc ,
24 is the name of a Lustre device, like
26 but may be a specific component, or contain wildcards to match some or all
27 devices on the node. Many parameters are readable as a regular user, though
28 some of them are accessible only by the root user for security or
29 implementation reasons.
33 Append a '/', '@', or '=' suffix for directories, symlinks, and writeable
34 parameters, respectively.
35 .B "lctl get_param -NF"
37 .BR "lctl list_param -F" .
40 Print only the parameter value and not parameter name. This may be confusing
41 if multiple parameter names are specified, as the parameters are not
42 identified, and may not be returned in the order that they are specified.
45 Print only matched parameter names and not the values. This is especially
46 useful when using patterns.
49 Recursively show all of the parameter names below the specified name.
52 Some paramters can be presented in a YAML format but are not by default. This
53 will format the parameter data in YAML. If the YAML provides a source: field
54 it can be suppressed with the -n option.
57 .B $ lctl get_param osc.*.max_pages_per_rpc
59 osc.myth-OST0000-osc-ffff8803c9c0f000.max_pages_per_rpc=1024
61 osc.myth-OST0001-osc-ffff8803c9c0f000.max_pages_per_rpc=1024
63 osc.testfs-OST0000-osc-ffff8803c9c0f000.max_pages_per_rpc=1024
65 osc.testfs-OST0001-osc-ffff8803c9c0f000.max_pages_per_rpc=1024
67 osc.testfs-OST0002-osc-ffff8803c9c0f000.max_pages_per_rpc=1024
69 .B $ lctl get_param -n debug
71 super warning dlmtrace error emerg rpctrace vfstrace config console
73 .B $ lctl get_param {mdc,osc}.testfs-*.max_rpcs_in_flight
75 mdc.testfs-MDT0000-mdc-ffff8803c9c0f000.max_rpcs_in_flight=16
77 osc.testfs-OST0000-osc-ffff8803c9c0f000.max_rpcs_in_flight=8
79 osc.testfs-OST0001-osc-ffff8803c9c0f000.max_rpcs_in_flight=8
81 osc.testfs-OST0002-osc-ffff8803c9c0f000.max_rpcs_in_flight=8
83 .B $ lctl get_param -n devices
85 0 UP osd-ldiskfs MGS-osd MGS-osd_UUID 4
87 .B $ lctl get_param -y devices
105 .BR lctl-list_param (8),
106 .BR lctl-set_param (8)