Viewing: mdt.enable_chprojid_gid.4
.TH MDT.ENABLE_CHPROJID_GID 4 2026-03-18 "Lustre" "Lustre Kernel Interfaces"
.SH NAME
mdt.enable_chprojid_gid \- control changing project ID of files
.SH SYNOPSIS
.SY
.RI "lctl get_param mdt." FSNAME *.enable_chprojid_gid= GID
.SY
.RI "lctl set_param mdt." FSNAME *.enable_chprojid_gid
.YS
.SS PROPERTIES
.TP
.B Access Permissions
.br
.BR 644 " | " -rw-r--r--
.TP
.B Scope
.br
Per-MDT device.
.TP
.B Config
.br
.B mdt.enable_chprojid_gid
is always present for MDT devices.
.TP
.B Default
.br
.RB enable_chprojid_gid= 0
.TP
.B Valid Range
.br
.RB enable_chprojid_gid= -1
.br
.RB enable_chprojid_gid= 4294967294
.SH DESCRIPTION
The integer argument
.I GID
controls which users in the given numeric group can change a file's project ID,
using commands such as
.BR lfs-project (1),
or
.BR chattr (1).
The project ID affects which quota limits apply to a given file or directory,
so allowing users to change this value may allow them to bypass quota limits.
The value
.B 0
indicates that only the root user is allowed to change the project ID of a
file or directory, while
.B \-1
means a user can change the projid on a file with suitable write permissions.
If
.I GID
is another value, it means users with that numeric Group ID that can change it.
For example, this could be used to allow an
.I admin
group for administrators, or a
.I chprojid
group for trusted users, using the numeric values of those groups.
.SH MODULES
This parameter is in the following modules:
.EX
.B mdt.*.enable_chprojid_gid
.EE
.SH EXAMPLES
To enable trusted users on the
.B testfs
filesystem to change projid:
.EX
.RB "mgs# " "getent group chprojid"
chprojid:x:509:adilger,rread,green
.RB "mgs# " "lctl set_param -P mdt.testfs-*.enable_chprojid_gid=509"
.EE
.SH AVAILABILITY
The
.B enable_chprojid_gid
parameter is part of the
.BR lustre (7)
filesystem package since release 2.14.0.
.\" Added in commit v2_13_50-95-g8fad70c087
.SH SEE ALSO
.BR chattr (1),
.BR lfs-project (1),
.BR lfs-quota (1),
.BR lfs-setquota (1),
.BR mdt.enable_pin_gid (4),
.BR mdt.enable_remote_dir_gid (4),
.BR projid (5),
.BR lctl-get_param (8)
.BR lctl-set_param (8)
