nfsdcltrack man page on Archlinux

Man page or keyword search:  
man Server   11224 pages
apropos Keyword Search (all sections)
Output format
Archlinux logo
[printable version]


       nfsdcltrack - NFSv4 Client Tracking Callout Program

       nfsdcltrack [-d] [-f] [-s stable storage dir] <command> <args...>

       nfsdcltack is the NFSv4 client tracking callout program. It is not
       necessary to install 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 program
       provides the userspace piece of that functionality. When the kernel
       needs to manipulate the database that stores this info, it will execute
       this program to handle it.

       -d, --debug
	   Enable debug level logging.

       -f, --foreground
	   Log to stderr instead of syslog.

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

       nfsdcltrack requires a command for each invocation. Supported commands

	   Initialize the database. This command requires no argument.

	   Create a new client record (or update the timestamp on an existing
	   one). This command requires a hex-encoded nfs_client_id4 as an

	   Remove a client record from the database. This command requires a
	   hex-encoded nfs_client_id4 as an argument.

	   Check to see if a nfs_client_id4 is allowed to reclaim. This
	   command requires a hex-encoded nfs_client_id4 as an argument.

	   Remove any unreclaimed client records from the database. This
	   command requires a epoch boot time as an argument.

       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. If the kernel passes the correct information, then nfsdcltrack
       can use it to allow a seamless transition from the old client tracking
       scheme to the new one.

       On a check operation, if there is no record of the client in the
       database, nfsdcltrack will look to see if the NFSDCLTRACK_LEGACY_RECDIR
       environment variable is set. If it is, then it will fetch that value
       and see if a directory exists by that name. If it does, then the check
       operation will succeed and the directory will be removed.

       On a gracedone operation, nfsdcltrack will look to see if the
       NFSDCLTRACK_LEGACY_TOPDIR environment variable is set. If it is, then
       it will attempt to clean out that directory prior to exiting.

       Note that this transition is one-way. If the machine subsequently
       reboots back into an older kernel that does not support the nfsdcltrack
       upcall then the clients will not be able to recover their state.

       This program requires a kernel that supports the nfsdcltrack
       usermodehelper upcall. This support was first added to mainline kernels
       in 3.8.

       nfsdcltrack was developed by Jeff Layton <>.

				  2012-10-24			NFSDCLTRACK(8)

List of man pages available for Archlinux

Copyright (c) for man pages and the logo by the respective OS vendor.

For those who want to learn more, the polarhome community provides shell access and support.

[legal] [privacy] [GNU] [policy] [cookies] [netiquette] [sponsors] [FAQ]
Polarhome, production since 1999.
Member of Polarhome portal.
Based on Fawad Halim's script.
Vote for polarhome
Free Shell Accounts :: the biggest list on the net