An NFS server can have export files on disk while the kernel service, export table, or mount discovery path is not ready for clients. A server-side status check shows whether the systemd unit is active, the kernel nfsd interface is exposed, and the intended export is loaded before client operators retry mounts.
Most systemd Linux servers manage the kernel NFS server through nfs-server.service. Current Ubuntu packages also provide nfs-kernel-server.service as an alias, while RHEL-family hosts use the same nfs-server.service unit name from nfs-utils.
Server-side commands confirm the host's own state. They do not prove that a remote client can cross the firewall, match an export selector, negotiate the intended NFS version, or access files with the expected UID/GID mapping.
Related: How to list NFS exports on a server
Related: How to reload NFS exports
Related: How to list NFS exports from a client
$ sudo systemctl is-active nfs-server active
Use nfs-kernel-server only when an older Debian or Ubuntu host exposes that name without the nfs-server alias.
$ sudo systemctl status nfs-server --no-pager
● nfs-server.service - NFS server and services
Loaded: loaded (/usr/lib/systemd/system/nfs-server.service; enabled; preset: enabled)
Active: active (exited) since Sun 2026-07-05 07:42:10 UTC; 2min 18s ago
Docs: man:rpc.nfsd(8)
man:exportfs(8)
Process: 1423 ExecStartPre=/usr/sbin/exportfs -r (code=exited, status=0/SUCCESS)
Process: 1428 ExecStart=/usr/sbin/rpc.nfsd (code=exited, status=0/SUCCESS)
active (exited) can be normal for this unit because systemd starts kernel nfsd threads and helper daemons instead of keeping one foreground process.
If the unit is inactive or failed, inspect sudo journalctl -u nfs-server before asking clients to retry.
$ cat /proc/fs/nfsd/threads 16
A positive number means kernel nfsd worker threads are present. A missing file usually means the nfsd filesystem is not mounted or the server unit has not started.
$ cat /proc/fs/nfsd/versions +3 +4 +4.1 +4.2
A plus sign means the server accepts that protocol version, and a minus sign means that version is disabled.
$ sudo exportfs -v /srv/nfs/projects 192.0.2.0/24(sync,wdelay,hide,no_subtree_check,sec=sys,rw,root_squash,no_all_squash)
exportfs -v reads the loaded export table, not only the saved /etc/exports text. If the expected path or selector is missing, reload the exports after fixing the source file.
$ showmount --exports localhost Export list for localhost: /srv/nfs/projects 192.0.2.0/24
NFSv4-only servers may not expose the mount service that showmount queries. Use the server-side exportfs table and a real client mount test for final proof on strict NFSv4 servers.
$ nfsstat --server Server rpc stats: calls badcalls badfmt badauth badclnt 128 0 0 0 0 Server nfs v4: null compound 0 0% 128 100%
Nonzero calls after a client test show that the server answered NFS traffic. Zero counters on an idle server do not by themselves mean the export is broken.
Related: How to check NFS server performance