Provided by: nfs-common_1.2.0-2ubuntu8_i386 bug

NAME

       sm-notify - Send out NSM reboot notifications

SYNOPSIS

       /sbin/sm-notify [-dfq] [-m time] [-p port] [-P path] [-v my_name ]

DESCRIPTION

       File  locking  over NFS (v2 and v3) requires a facility to notify peers
       in case of a reboot, so that clients can reclaim locks after  a  server
       crash, and/or servers can release locks held by the rebooted client.

       This  is  a  two-step process: during normal operations, a mechanism is
       required to keep track of which hosts need to be informed of a  reboot.
       And  of  course,  notifications need to be sent out during reboot.  The
       protocol used for this is called NSM, for Network Status Monitor.

       This implementation separates these into separate  program.   rpc.statd
       tracks  hosts which need to be notified and this sm-notify performs the
       notification.  When rpc.statd is started it will typically started  sm-
       notify but this is configurable.

   Operation
       For  each  NFS  client  or  server  machine  to be monitored, rpc.statd
       creates a file in /var/lib/nfs/sm, and removes the file  if  monitoring
       is no longer required.

       When  the  machine  is rebooted, sm-notify iterates through these files
       and notifies the peer statd server on those machines.

       Each machine has an NSM state , which is basically an  integer  counter
       that  is  incremented  each  time  the machine reboots. This counter is
       stored in /var/lib/nfs/state, and updated by sm-notify.

   Security
       sm-notify has little need for root privileges and so drops them as soon
       as possible.  It continues to need to make changes to the sm and sm.bak
       directories so to be able to drop privileges, these must be writable by
       a  non-privileged  user.   If these directories are owned by a non-root
       user, sm-notify will drop privilege to match  that  user  once  it  has
       created sockets for sending out request (for which it needs privileged)
       but before it processes any reply (which is the most likely  source  of
       possible privilege abuse).

OPTIONS

       -m failtime
              When  notifying  hosts,  sm-notify will try to contact each host
              for up to 15 minutes, and will give up if  unable  to  reach  it
              within this time frame.

              Using  the  -m option, you can override this. A value of 0 tells
              sm-notify to retry indefinitely; any other value is  interpreted
              as the maximum retry time in minutes.

       -v ipaddr-or-hostname
              This option tells sm-notify to bind to the specified ipaddr, (or
              the ipaddr of the  given  hostname)  so  that  all  notification
              packets  originate  from  this  address.  This is useful for NFS
              failover.  The given name is also used as the name of this  host
              in the NSM request.

       -p port
              instructs  sm-notify to bind to the indicated IP port number. If
              this option is not given, it will try  to  bind  to  a  randomly
              chosen privileged port below 1024.

       -q     Be  quiet.  This  suppresses  all messages except error messages
              while collecting the list of hosts.

       -P /path/to/state/directory
              If sm-notify should look in a no-standard place of  state  file,
              the  path  can be given here.  The directories sm and sm.bak and
              the file state must exist in that directory  with  the  standard
              names.

       -f     If  the  state  path  has not been reset with -P, sm-notify will
              normally create a file in /var/run to indicate that it has  been
              run.   If  this file is found when sm-notify starts, it will not
              run again (as it is normally only needed once per  reboot).   If
              -f  (for force) is given, sm-notify will run even if the file in
              /var/run is present.

       -n     Do not update the NSM state. This is for testing only.   Setting
              this flag implies -f.

       -d     Enables  debugging.  By default, sm-notify forks and puts itself
              in the  background  after  obtaining  the  list  of  hosts  from
              /var/lib/nfs/sm.

FILES

       /var/lib/nfs/state
       /var/lib/nfs/sm/*
       /var/lib/nfs/sm.bak/*
       /var/run/sm-notify.pid

SEE ALSO

       rpc.nfsd(8), portmap(8)

AUTHORS

       Olaf Kirch <okir@suse.de>

                                  19 Mar 2007                     sm-notify(8)