source: gpfs_3.1_ker2.6.20/lpp/mmfs/samples/nfscluster/nfsnodeback @ 86

#!/bin/ksh
# @(#)65  1.5.1.2  src/avs/fs/mmfs/samples/nfscluster/nfsnodeback, mmfs, avs_rgpfs24, rgpfs24s006a 8/17/06 17:09:15
#

if [ ! -f /var/mmfs/etc/nfsfuncs ]; then
    echo "$0: Can't find NFS functions in /var/mmfs/etc"
    exit 0
fi
. /var/mmfs/etc/nfsfuncs

debugmsg "gpfs_ip $1 failover_ip $2 recovering_ip $3"

hard_failback() {
    [ $# -lt 3 ] && die "Usage: $0 gpfs_ip failover_ip"

    gpfs_ip=$1
    failover_ip=$2
    recovering_ip=$3

    # 1. all nodes go in to grace period
    # Note: this is already done by nfsgrace
    # startGrace
    # msg "NLM grace period started due to recovery of node ($recovering_ip)"

    # 2. only recovery node release IP addresses of node that joined back
    if [ "$gpfs_ip" == "$failover_ip" ]; then
        nfsips=$(getNfsIPs $recovering_ip)
        msg "Node $recovering_ip has recovered; releasing its IP address(es) $nfsips"

  [ $hardMount -eq 1 ] && nfsService soft-restart

        for ip in $nfsips; do
      ifDown $ip
        done
    fi

    # 3. all node start lock recovery
    startReclaim $gpfs_ip
}

soft_failback() {
    [ $# -lt 2 ] && die "Usage: $0 gpfs_ip failover_ip"
    gpfs_ip=$1
    recovering_ip=$2

    nfsips=$(getNfsIPs $recovering_ip)
    msg "Node $recovering_ip has recovered; releasing its IP address(es) $nfsips"

    [ $hardMount -eq 1 ] && nfsService soft-restart

    for ip in $nfsips; do
        ifDown $ip
    done

    resetLockd

    msg "All NLM locks have been released due to recovery of node ($recovering_ip)"
    startReclaim $gpfs_ip
    for failed_node in $(ls -A $SHARED_RECOVERY/$gpfs_ip); do
        startReclaim $failed_node
    done
}

if [ $# -ge 3 ]; then
    hard_failback $*
else
    soft_failback $*
fi