运行于centos6.5的rbdmap：
[root@mon0 ceph]# cat /etc/init.d/rbdmap #!/bin/bash## rbdmap Ceph RBD Mapping## chkconfig: 2345 70 70# description: Ceph RBD Mapping### BEGIN INIT INFO# Provides: rbdmap# Required-Start: $network $remote_fs# Required-Stop: $network $remote_fs# Should-Start: ceph# Should-Stop: ceph# X-Start-Before: $x-display-manager# Default-Start: 2 3 4 5# Default-Stop: 0 1 6# Short-Description: Ceph RBD Mapping# Description: Ceph RBD Mapping### END INIT INFODESC="RBD Mapping:"RBDMAPFILE="/etc/ceph/rbdmap". /lib/lsb/init-functionsdo_map() { if [ ! -f "$RBDMAPFILE" ]; then #log_warning_msg "$DESC : No $RBDMAPFILE found." exit 0 fi # Read /etc/rbdtab to create non-existant mapping RET=0 while read DEV PARAMS; do case "$DEV" in ""|\#*) continue ;; */*) ;; *) DEV=rbd/$DEV ;; esac #log_action_begin_msg "${DESC} '${DEV}'" newrbd="" MAP_RV="" RET_OP=0 OIFS=$IFS IFS=',' for PARAM in ${PARAMS[@]}; do CMDPARAMS="$CMDPARAMS --$(echo $PARAM | tr '=' ' ')" done IFS=$OIFS if [ ! -b /dev/rbd/$DEV ]; then MAP_RV=$(rbd map $DEV $CMDPARAMS 2>&1) if [ $? -eq 0 ]; then newrbd="yes" else RET=$((${RET}+$?)) RET_OP=1 fi fi #log_action_end_msg ${RET_OP} "${MAP_RV}" if [ "$newrbd" ]; then ## Mount new rbd MNT_RV="" mount --fake /dev/rbd/$DEV >>/dev/null 2>&1 \ && MNT_RV=$(mount -v /dev/rbd/$DEV 2>&1) [ -n "${MNT_RV}" ] && log_action_msg "mount: ${MNT_RV}" ## post-mapping if [ -x "/etc/ceph/rbd.d/${DEV}" ]; then #log_action_msg "RBD Running post-map hook '/etc/ceph/rbd.d/${DEV}'" /etc/ceph/rbd.d/${DEV} map "/dev/rbd/${DEV}" fi fi done < $RBDMAPFILE exit ${RET}}do_unmap() { RET=0 ## Unmount and unmap all rbd devices if ls /dev/rbd[0-9]* >/dev/null 2>&1; then for DEV in /dev/rbd[0-9]*; do ## pre-unmapping for L in $(find /dev/rbd -type l); do LL="${L##/dev/rbd/}" if [ "$(readlink -f $L)" = "${DEV}" ] \ && [ -x "/etc/ceph/rbd.d/${LL}" ]; then log_action_msg "RBD pre-unmap: '${DEV}' hook '/etc/ceph/rbd.d/${LL}'" /etc/ceph/rbd.d/${LL} unmap "$L" break fi done #log_action_begin_msg "RBD un-mapping: '${DEV}'" UMNT_RV="" UMAP_RV="" RET_OP=0 MNT=$(findmnt --mtab --source ${DEV} --noheadings | awk '{print $1'}) if [ -n "${MNT}" ]; then # log_action_cont_msg "un-mounting '${MNT}'" UMNT_RV=$(umount "${MNT}" 2>&1) fi if mountpoint -q "${MNT}"; then ## Un-mounting failed. RET_OP=1 RET=$((${RET}+1)) else ## Un-mapping. UMAP_RV=$(rbd unmap $DEV 2>&1) if [ $? -ne 0 ]; then RET=$((${RET}+$?)) RET_OP=1 fi fi #log_action_end_msg ${RET_OP} "${UMAP_RV}" [ -n "${UMNT_RV}" ] && log_action_msg "${UMNT_RV}" done fi exit ${RET}}case "$1" in start) do_map ;; stop) do_unmap ;; restart|force-reload) $0 stop $0 start ;; reload) do_map ;; status) rbd showmapped ;; *) log_success_msg "Usage: rbdmap {start|stop|restart|force-reload|reload|status}" exit 1 ;;esac 修改一些在centos上没有的log后，这个脚本使用起来还是有问题，具体描述如下：
1. 在只rbd map一个块得到/dev/rbd0后，使用rbdmap脚本可以正常map/unmap /dev/rbd0。
2. 当将/dev/rbd0格式化后挂载到一个目录上，再使用rbdmap，关机的时候系统就会hang在unmounting filesystem上了，只能强制断电；再开机启动后执行了rbdmap的do_map()函数，一切正常。
排查后发现，当将/dev/rbd0挂载到目录后，rbdmap就不会执行do_unmap()函数，即使函数中加入显式umount操作也不会执行。
想了一个折中的办法，在rbdmap停止优先级高的服务中的stop函数中显式加入umount操作，重启时一切正常了。
先来看一下ceph、rbdmap的启停顺序：
head rbdmap#!/bin/bash## rbdmap Ceph RBD Mapping## chkconfig: 2345 70 70# description: Ceph RBD Mappinghead ceph#!/bin/sh# Start/stop ceph daemons# chkconfig: - 60 80### BEGIN INIT INFO# Provides: ceph# Default-Start:# Default-Stop:# Required-Start: $remote_fs $named $network $time# Required-Stop: $remote_fs $named $network $time可以看出ceph先于rbdmap启动，rbdmap先于ceph停止。如果采用nfs，使用rbdmap映射出的块设备，先看看nfs的启停顺序：
head /etc/init.d/nfs#!/bin/sh## nfs This shell script takes care of starting and stopping# the NFS services.## chkconfig: - 30 60# description: NFS is a popular protocol for file sharing across networks.# This service provides NFS server functionality, which is \# configured via the /etc/exports file.# probe: truenfs是这三者中最先启动的，也是最先停止的。所以在nfs的stop函数中加入umount命令：
umount /mnt/nfsumount /mnt/nfs2在rbdmap中加入挂载命令：
mount /dev/rbd0 -o rw,noexec,nodev,noatime,nobarrier,discard /mnt/nfsmount /dev/rbd1 -o rw,noexec,nodev,noatime,nobarrier,discard /mnt/nfs2/etc/ceph/rbdmap的设置如下：
backup1/backup.imgbackup2/backup.img
记得在ceph-0.80时测试是没有问题的，到了0.87.1出现了上述问题，有时间读读rbdmap脚本。