Mount and transport state

Normally, the mountstats command shows NFS mount status. We have extended the interface it uses, /proc/self/mountstats, with our own extra state reporting via /sys. The extended information contains the IP addresses related to the transport, and a string that indicates its state flags.

The extended form of it is obtainable via /sys/kernel/debug. For the association to an NFS mount, we need to obtain the related sunrpc-id of the mount point.

But first, we need to enable sunrpc-id reporting. This can be done using the following command after boot:

echo 1 | sudo tee /sys/module/sunrpc/parameters/expose_id_in_mountstats

Then, identify the sunrpc-id relevant to the mount point by looking into /proc/self/mountstats:

$ cat /proc/self/mountstats | grep -E 'fstype nfs|sunrpc-id'
device 192.168.40.7:/opt/export mounted on /mnt/export with fstype nfs statvers=1.1
        sunrpc-id:      4

Now we are ready to fetch the full mountstats via the following command:

    sudo cat /sys/kernel/debug/sunrpc/rpc_clnt/4/stats

The added information contains multipath IP address information per xprt (transport) and xprt state in string format. The numbers in the first xprt: line are counters and other numbers related that transports.

For example:

        xprt:   rdma 0 0 1 0 24 3 3 0 3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0
                172.25.1.101 -> 172.25.1.1, state: CONNECTED BOUND
        xprt:   rdma 0 0 1 0 24 1 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0
                172.25.1.102 -> 172.25.1.2, state: CONNECTED BOUND
        xprt:   rdma 0 0 1 0 23 1 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0
                172.25.1.103 -> 172.25.1.3, state: CONNECTED BOUND
        xprt:   rdma 0 0 1 0 22 1 1 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 11 0 0 0
                172.25.1.104 -> 172.25.1.4, state: CONNECTED BOUND
        xprt:   rdma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
                172.25.1.101 -> 172.25.1.5, state: BOUND
        xprt:   rdma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
                172.25.1.102 -> 172.25.1.6, state: BOUND
        xprt:   rdma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
                172.25.1.103 -> 172.25.1.7, state: BOUND
        xprt:   rdma 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
                172.25.1.104 -> 172.25.1.8, state: BOUND

Document generated on 2025.06.13 19:31 for v4.0.34, branch 4.0