servername:~ # cat /etc/idmapd.conf
[General]
Verbosity = 0
Pipefs-Directory = /var/lib/nfs/rpc_pipefs
Domain = good.domain
[Mapping]
Nobody-User = nobody
Nobody-Group = nobody
servername:~ #
servername:~ # systemctl stop nfs-idmapd.service
servername:~ # systemctl start nfs-idmapd.service
servername:~ # nfsidmap -c
servername:~ # umount /usr/bar/foo
servername:~ # mount /usr/bar/foo
servername:~ # mount|grep -w /usr/bar/foo
192.168.0.12:/foo_shared_usr_bar_node2 on /usr/bar/foo type nfs4 (rw,noatime,vers=4.1,rsize=65536,wsize=65536,namlen=255,hard,proto=tcp,timeo=600,retrans=2,sec=null,clientaddr=192.168.0.210,local_lock=none,addr=192.168.0.12)
servername:~ # su - fooadm
fooadm@servername:/usr/bar/foo/foo204> df -h .
Filesystem Size Used Avail Use% Mounted on
192.168.0.12:/foo_shared 256G 7.9G 249G 4% /bar2/shared/foo
fooadm@servername:/usr/bar/foo/foo204> touch testing
fooadm@servername:/usr/bar/foo/foo204> ls -lah testing
-rw-r----- 1 root daemon 0 Apr 27 15:30 testing
fooadm@servername:/usr/bar/foo/foo204> logout
servername:~ # systemctl status nfs-idmapd.service
● nfs-idmapd.service - NFSv4 ID-name mapping service
Loaded: loaded (/usr/lib/systemd/system/nfs-idmapd.service; static; vendor preset: disabled)
Active: active (running) since Wed 2022-04-27 15:29:35 CEST; 3min 36s ago
Process: 34781 ExecStart=/usr/sbin/rpc.idmapd $RPCIDMAPDARGS (code=exited, status=0/SUCCESS)
Main PID: 34782 (rpc.idmapd)
Tasks: 1 (limit: 512)
CGroup: /system.slice/nfs-idmapd.service
└─34782 /usr/sbin/rpc.idmapd
Apr 27 15:29:34 servername systemd[1]: Starting NFSv4 ID-name mapping service...
Apr 27 15:29:35 servername systemd[1]: Started NFSv4 ID-name mapping service.
servername:~ #
but it works with NFSv4.0, only issue is on 4.1.
The Question: why do files get root:daemon on NFSv4.1? It works perfectly fine on NFSv4.0 (files will be created with fooadm:anditsgoodgroup)! Only diff is the version number.