我们在某一集群中使用ISCSI+GFS2的时候，某个节点重启的时候卡在下面这个地方，直接卡死。

md: stopping all md devices. 

Synchronizing SCSI cache for disk sda

根据排查发现是/etc/init.d/iscsi脚本的问题
stop()
{
    rm -f /var/lock/subsys/iscsi

    # If this is a final shutdown/halt, do nothing since
    # lvm/dm, md, power path, etc do not always handle this
#    if [ "$RUNLEVEL" = "6" -o "$RUNLEVEL" = "0" -o "$RUNLEVEL" = "1" ]; then
#        success
#        return
#    fi

    # don't turn off iscsi if root is possibly on a iscsi disk
    rootopts=$(awk '{ if ($1 !~ /^[ \t]*#/ && $2 == "/") { print $4; }}' /etc/mtab)
    if [[ "$rootopts" =~ "_netdev" ]] ; then
        echo $"Can not shutdown iSCSI. Root is on a iSCSI disk."
        exit 1
    fi

    iscsiadm -m node --logoutall=all
    /etc/init.d/iscsid stop
    success
}

#    if [ "$RUNLEVEL" = "6" -o "$RUNLEVEL" = "0" -o "$RUNLEVEL" = "1" ]; then
#        success
#        return
#   将这三行注释即可正常重启。