NFSDCLD(8)                                                        NFSDCLD(8)

NAME         top

       nfsdcld - NFSv4 Client Tracking Daemon

SYNOPSIS         top

       nfsdcld [-d] [-F] [-p path] [-s stable storage dir]

DESCRIPTION         top

       nfsdcld is the NFSv4 client tracking daemon. It is not necessary to
       run this daemon on machines that are not acting as NFSv4 servers.

       When a network partition is combined with a server reboot, there are
       edge conditions that can cause the server to grant lock reclaims when
       other clients have taken conflicting locks in the interim. A more
       detailed explanation of this issue is described in RFC 3530, section

       In order to prevent these problems, the server must track a small
       amount of per-client information on stable storage. This daemon
       provides the userspace piece of that functionality.

OPTIONS         top

       -d, --debug
           Enable debug level logging.

       -F, --foreground
           Runs the daemon in the foreground and prints all output to stderr

       -p path, --pipefsdir=path
           Location of the rpc_pipefs filesystem. The default value is

       -s storage_dir, --storagedir=storage_dir
           Directory where stable storage information should be kept. The
           default value is /var/lib/nfs/nfsdcld.


       The following values are recognized in the [nfsdcld] section of the
       /etc/nfs.conf configuration file:

           Equivalent to -s/--storagedir.

           Setting "debug = 1" is equivalent to -d/--debug.

       In addition, the following value is recognized from the [general]

           Equivalent to -p/--pipefsdir.

NOTES         top

       The Linux kernel NFSv4 server has historically tracked this
       information on stable storage by manipulating information on the
       filesystem directly, in the directory to which
       /proc/fs/nfsd/nfsv4recoverydir points.

       This daemon requires a kernel that supports the nfsdcld upcall. If
       the kernel does not support the new upcall, or is using the legacy
       client name tracking code then it will not create the pipe that
       nfsdcld uses to talk to the kernel.

       This daemon should be run as root, as the pipe that it uses to
       communicate with the kernel is only accessable by root. The daemon
       however does drop all superuser capabilities after starting. Because
       of this, the storagedir should be owned by root, and be readable and
       writable by owner.

AUTHORS         top

       The nfsdcld daemon was developed by Jeff Layton <>.

COLOPHON         top

       This page is part of the nfs-utils (NFS utilities) project.
       Information about the project can be found at 
       ⟨⟩.  If you have a bug
       report for this manual page, see
       ⟨⟩.  This page was
       obtained from the project's upstream Git repository
       ⟨;a=summary⟩ on
       2019-07-28.  (At that time, the date of the most recent commit that
       was found in the repository was 2019-07-24.)  If you discover any
       rendering problems in this HTML version of the page, or you believe
       there is a better or more up-to-date source for the page, or you have
       corrections or improvements to the information in this COLOPHON
       (which is not part of the original manual page), send a mail to

                                 2011-12-21                       NFSDCLD(8)