Viewing: ldlm.ldlm_enqueue_min.4
.TH LDLM.LDLM_ENQUEUE_MIN 4 2026-03-31 Lustre "Lustre Kernel Interfaces"
.SH NAME
ldlm.ldlm_enqueue_min \- lock enqueue timeout minimum
.SH SYNOPSIS
.SY
.B "lctl get_param ldlm.ldlm_enqueue_min"
.SY
.B "lctl get_param osc." FSNAME "-*.ldlm_enqueue_min"
.SY
.BI "lctl set_param ldlm.ldlm_enqueue_min=" TIMEOUT_SECONDS
.SY
.BI "lctl set_param osc." FSNAME "-*.ldlm_enqueue_min=" TIMEOUT_SECONDS
.YS
.SS PROPERTIES
.TP
.B Access Permissions
.BR 644 " | " -rw-r--r--
.TP
.B Scope
.br
Global
.TP
.B Config
.br
Always present
.TP
.B Default
.br
.RB ldlm.ldlm_enqueue_min= 100
.TP
.B Valid Range
.br
.RB ldlm.ldlm_enqueue_min= 10
.br
.RB ldlm.ldlm_enqueue_min= 900 | at_max
.SH DESCRIPTION
.B ldlm_enqueue_min
is the minimum lock enqueue time.
The time it takes to enqueue a lock, shown as the ldlm_enqueue operation in the
stats files, is the maximum of the measured enqueue estimate
(influenced by at_min and at_max parameters),
multiplied by a weighting factor and the value of ldlm_enqueue_min.
.PP
Lustre Distributed Lock Manager (LDLM) lock enqueues have a dedicated minimum
ldlm_enqueue_min. Lock enqueue timeouts increase as the measured enqueue times
increase (similar to adaptive timeouts).
.PP
It is preferred to set
.B ldlm_enqueue_min
as a per-target tunable with
.BI osc. FSNAME -*.ldlm_enqueue_min
instead of the global parameter.
This avoids issues if a client mounts multiple filesystems with different
.B ldlm_enqueue_min
tunable settings.
.SH MODULES
This parameter is in the following modules:
.EX
.B ldlm.ldlm_enqueue_min
.br
.B osc.*.ldlm_enqueue_min
.EE
.SH EXAMPLES
Set the minimum enqueue timeout to 50s for the
.B testfs
filesystem:
.EX
.RB mgs# "lctl set_param -P *.testfs*.ldlm_enqueue_min=50"
.EE
.SH AVAILABILITY
.B ldlm_enqueue_min
is part of the
.BR lustre (7)
filesystem package since release 1.6.4,
.\" commit 1.6.0-1416-gde3c3fdf25
but the per-subsystem tunables are only present since release 2.18.0.
.\" commit v2_17_51-8-gb1da541f7a
.SH SEE ALSO
.BR at_early_margin (4),
.BR at_extra (4),
.BR at_history (4),
.BR at_max (4),
.BR at_min (4)
