diff --git a/scripts/xe-backup-metadata b/scripts/xe-backup-metadata
index 369e489c218..35fa31a5e94 100755
--- a/scripts/xe-backup-metadata
+++ b/scripts/xe-backup-metadata
@@ -74,7 +74,7 @@ function validate_vdi_uuid {
 function test_sr {
   sr_uuid_found=$(${XE} sr-list uuid="$1" --minimal)
   if [ "${sr_uuid_found}" != "$1" ]; then
-     echo Invalid SR UUID specified: $1
+     echo "Invalid SR UUID specified: $1"
      usage
   fi
 }
@@ -112,32 +112,32 @@ fi
 # determine if the SR UUID is vaid
 if [  -z "${sr_uuid}" ]; then
   # use the default-SR from the pool
-  sr_uuid=$(${XE} pool-param-get uuid=${pool_uuid} param-name=default-SR)
+  sr_uuid=$(${XE} pool-param-get uuid="${pool_uuid}" param-name=default-SR)
 fi
 test_sr "${sr_uuid}"
 
 sr_name=$(${XE} sr-param-get uuid="${sr_uuid}" param-name=name-label)
 # see if a backup VDI already exists on the selected SR
-vdi_uuid=$(${XE} vdi-list other-config:ctxs-pool-backup=true sr-uuid=${sr_uuid} params=uuid --minimal)
+vdi_uuid=$(${XE} vdi-list other-config:ctxs-pool-backup=true sr-uuid="${sr_uuid}" params=uuid --minimal)
 
 mnt=
 function cleanup {
    trap "" TERM INT
    cd /
    if [ ! -z "${mnt}" ]; then
-      umount ${mnt} >/dev/null 2>&1
-      rmdir ${mnt}
+      umount "${mnt}" >/dev/null 2>&1
+      rmdir "${mnt}"
    fi
 
    if [ ! -z "${vbd_uuid}" ]; then
       ${debug} echo -n "Unplugging VBD: "
-      ${XE} vbd-unplug uuid=${vbd_uuid} timeout=20
+      ${XE} vbd-unplug uuid="${vbd_uuid}" timeout=20
       # poll for the device to go away if we know its name
       if [ "${device}" != "" ]; then
           device_gone=0
           for ((i=0; i<10; i++)); do
               ${debug} echo -n "."
-              if [ ! -b ${device} ]; then
+              if [ ! -b "${device}" ]; then
                   ${debug} echo " done"
                   device_gone=1
                   break
@@ -146,14 +146,14 @@ function cleanup {
           done
           if [ ${device_gone} -eq 0 ]; then
               ${debug} echo " failed"
-              echo Please destroy VBD ${vbd_uuid} manually.
+              echo "Please destroy VBD ${vbd_uuid} manually."
           else
-              ${XE} vbd-destroy uuid=${vbd_uuid}
+              ${XE} vbd-destroy uuid="${vbd_uuid}"
           fi
       fi
    fi
    if [ ${fs_uninitialised} -eq 1 -a -n "${vdi_uuid}" ] ; then
-      ${XE} vdi-destroy uuid=${vdi_uuid}
+      ${XE} vdi-destroy uuid="${vdi_uuid}"
    fi
 }
 
@@ -184,8 +184,8 @@ if [ -z "${vdi_uuid}" ]; then
     echo "Backup VDI not found, aborting.  You can initialise one using the '-c' flag."
     exit 3
   fi
-  echo ${vdi_uuid}
-  ${XE} vdi-param-set uuid=${vdi_uuid} other-config:ctxs-pool-backup=true
+  echo "${vdi_uuid}"
+  ${XE} vdi-param-set uuid="${vdi_uuid}" other-config:ctxs-pool-backup=true
 else
   ${debug} echo "Using existing backup VDI: ${vdi_uuid}"
   fs_uninitialised=0
@@ -196,71 +196,71 @@ if [ ${just_find_vdi} -gt 0 ]; then
 fi
 
 ${debug} echo -n "Creating VBD: "
-vbd_uuid=$(${XE} vbd-create vm-uuid=${CONTROL_DOMAIN_UUID} vdi-uuid=${vdi_uuid} device=autodetect)
-${debug} echo ${vbd_uuid}
+vbd_uuid=$(${XE} vbd-create vm-uuid="${CONTROL_DOMAIN_UUID}" vdi-uuid="${vdi_uuid}" device=autodetect)
+${debug} echo "${vbd_uuid}"
 
 
 if [ $? -ne 0 -o -z "${vbd_uuid}" ]; then
-  echo error creating VBD
+  echo "error creating VBD"
   cleanup
   exit 1
 fi
 
 ${debug} echo -n "Plugging VBD: "
-${XE} vbd-plug uuid=${vbd_uuid}
-device=/dev/$(${XE} vbd-param-get uuid=${vbd_uuid} param-name=device)
+${XE} vbd-plug uuid="${vbd_uuid}"
+device=/dev/$(${XE} vbd-param-get uuid="${vbd_uuid}" param-name=device)
 
-if [ ! -b ${device} ]; then
-  ${debug} echo ${device}: not a block special
+if [ ! -b "${device}" ]; then
+  ${debug} echo "${device}: not a block special"
   cleanup
   exit 1
 fi
 
-${debug} echo ${device}
+${debug} echo "${device}"
 
-if [ $init_fs -eq 1 ]; then
+if [ "$init_fs" -eq 1 ]; then
   ${debug} echo -n "Creating filesystem: "
-  mkfs.ext3 -j -F ${device} > /dev/null 2>&1
+  mkfs.ext3 -j -F "${device}" > /dev/null 2>&1
   ${debug} echo "done"
   fs_uninitialised=0
 fi
 
 ${debug} echo -n "Mounting filesystem: "
-mnt=/var/run/pool-backup-${vdi_uuid}
-mkdir -p ${mnt}
+mnt="/var/run/pool-backup-${vdi_uuid}"
+mkdir -p "${mnt}"
 
-/sbin/fsck -a ${device} >/dev/null 2>&1
+/sbin/fsck -a "${device}" >/dev/null 2>&1
 if [ $? -ne 0 ]; then
   ${debug} fsck failed.  Please correct manually
   cleanup 
   exit 1
 fi
 
-mount ${device} ${mnt} > /dev/null 2>&1
+mount "${device}" "${mnt}" > /dev/null 2>&1
 if [ $? -ne 0 ]; then
   ${debug} echo failed
   cleanup
   exit 1
 fi
-${debug} echo ${mnt}
+${debug} echo "${mnt}"
 
 if [ ${leave_mounted} -eq 0 ]; then
-  lrconf=${mnt}/conf/${vdi_uuid}
-  if [ ! -f ${lrconf} ]; then
+  lrconf="${mnt}/conf/${vdi_uuid}"
+  if [ ! -f "${lrconf}" ]; then
      ${debug} echo -n "Initialising rotation: "
-     mkdir -p ${mnt}/conf/ 
-     echo "${mnt}/${pool_uuid}.db {" >> ${lrconf}
-     echo "    rotate ${history_kept}" >> ${lrconf}
-     echo "    missingok" >> ${lrconf}
-     echo "}" >> ${lrconf}
-     echo done
-     echo ${metadata_version} >> ${mnt}/.ctxs-metadata-backup
+     mkdir -p "${mnt}/conf/"
+     echo "${mnt}/${pool_uuid}.db {" >> "${lrconf}"
+     echo "    rotate ${history_kept}" >> "${lrconf}"
+     echo "    missingok" >> "${lrconf}"
+     echo "}" >> "${lrconf}"
+     echo "done"
+     echo "${metadata_version}" >> "${mnt}/.ctxs-metadata-backup"
   fi
 
   # check the usage of the backup VDI
-  usage=`cd ${mnt} && df . | sed -n "2p" | awk '{ print $5 }' | tr -d '%'`
+  usage=`cd "${mnt}" && df . | sed -n "2p" | awk '{ print $5 }' | tr -d '%'`
   echo "Checking backup VDI space usage: $usage%"
-  if [ $usage -gt $usage_alert ] && [ ${force_backup} -eq 0 ]; then
+  if [ "$usage" -gt "$usage_alert" ] && [ "${force_backup}" -eq 0 ]; then
     echo "Running out of space, you can use '-d' option to attach VDI and free more space, exit now."
     cleanup
     exit 1
@@ -268,38 +268,38 @@ if [ ${leave_mounted} -eq 0 ]; then
 
   # invoke logrotate to rotate over old pool db backups
   echo -n "Rotating old backups: "
-  logrotate -f ${lrconf}
-  num_found=$(find ${mnt} -name \*.db\.* | wc -l)
-  echo found ${num_found}
+  logrotate -f "${lrconf}"
+  num_found=$(find "${mnt}" -name '*.db.*' | wc -l)
+  echo "found ${num_found}"
   
   # perform the pool database dump
   echo -n "Backing up pool database: "
-  ${XE} pool-dump-database file-name=${mnt}/${pool_uuid}.db
+  ${XE} pool-dump-database file-name="${mnt}/${pool_uuid}.db"
   echo done
 
   # backup the VM metadata for each VM in the pool into a dated directory
   datetime=$(date +%F-%H-%M-%S)
-  metadir=${mnt}/metadata/${datetime}
-  mkdir -p ${metadir}
+  metadir="${mnt}/metadata/${datetime}"
+  mkdir -p "${metadir}"
   echo -n "Cleaning old VM metadata: "
   IFS=" "
-  todelete=$(cd ${mnt}/metadata && ls -1 |sort -n | head -n -${history_kept} | xargs echo)
+  todelete=$(cd "${mnt}/metadata" && ls -1 |sort -n | head -n -${history_kept} | xargs echo)
   for dir in ${todelete}; do
-    rm -rf ${mnt}/metadata/${dir}
+    rm -rf "${mnt}/metadata/${dir}"
   done
   echo done
   IFS=","
   echo -n "Backing up SR metadata: "
-  mkdir -p ${metadir}
-  "@LIBEXECDIR@/backup-sr-metadata.py" -f ${metadir}/SRMETA.xml
+  mkdir -p "${metadir}"
+  "@LIBEXECDIR@/backup-sr-metadata.py" -f "${metadir}/SRMETA.xml"
   echo "done"
 
   echo -n "Backing up VM metadata: "
   ${debug} echo ""
-  mkdir -p ${metadir}/all
+  mkdir -p "${metadir}/all"
   for vmuuid in $(${XE} vm-list params=uuid is-control-domain=false --minimal); do
     ${debug} echo -n .
-    ${XE} vm-export --metadata uuid=${vmuuid} filename=${metadir}/all/${vmuuid}.vmmeta >/dev/null 2>&1
+    ${XE} vm-export --metadata uuid="${vmuuid}" filename="${metadir}/all/${vmuuid}.vmmeta" >/dev/null 2>&1
   done
   echo "done"
   echo -n "Backing up Template metadata: "
@@ -307,13 +307,13 @@ if [ ${leave_mounted} -eq 0 ]; then
   template_uuids=$("@LIBEXECDIR@/print-custom-templates")
   if [ $? -eq 0 ]; then
       for tmpl_uuid in ${template_uuids}; do
-          ${XE} template-export --metadata template-uuid=${tmpl_uuid} filename=${metadir}/all/${tmpl_uuid}.vmmeta >/dev/null 2>&1
+          ${XE} template-export --metadata template-uuid="${tmpl_uuid}" filename="${metadir}/all/${tmpl_uuid}.vmmeta" >/dev/null 2>&1
       done
   fi
   echo "done"
-  "@LIBEXECDIR@/link-vms-by-sr.py" -d ${metadir}
+  "@LIBEXECDIR@/link-vms-by-sr.py" -d "${metadir}"
 else
-  cd ${mnt}
+  cd "${mnt}"
   env PS1="Mounted backup VDI on: ${mnt}\nPress ^D to exit shell and safely detach it.\n\n[\u@\h \W]\$ " bash
 fi
 
diff --git a/scripts/xe-restore-metadata b/scripts/xe-restore-metadata
index cdcf0d7f495..9018fe85875 100755
--- a/scripts/xe-restore-metadata
+++ b/scripts/xe-restore-metadata
@@ -55,7 +55,7 @@ function usage {
 function test_sr {
   sr_uuid_found=$(${XE} sr-list uuid="$1" --minimal)
   if [ "${sr_uuid_found}" != "$1" ]; then
-     echo Invalid SR UUID specified: $1
+     echo "Invalid SR UUID specified: $1"
      usage
   fi
 }
@@ -109,11 +109,11 @@ fi
 # determine if the SR UUID is vaid
 if [  -z "${sr_uuid}" ]; then
   # use the default-SR from the pool
-  sr_uuid=$(${XE} pool-param-get uuid=${pool_uuid} param-name=default-SR)
+  sr_uuid=$(${XE} pool-param-get uuid="${pool_uuid}" param-name=default-SR)
 fi
 test_sr "${sr_uuid}"
 
-sr_name=$(${XE} sr-param-get uuid=${sr_uuid} param-name=name-label)
+sr_name=$(${XE} sr-param-get uuid="${sr_uuid}" param-name=name-label)
 
 # probe first for a VDI with known UUID derived from the SR to avoid
 # scanning for a VDI
@@ -131,20 +131,20 @@ mnt=
 function cleanup {
    cd /
    if [ ! -z "${mnt}" ]; then
-      umount ${mnt} >/dev/null 2>&1
-      rmdir ${mnt}
+      umount "${mnt}" >/dev/null 2>&1
+      rmdir "${mnt}"
       mnt=""
    fi
 
    if [ ! -z "${vbd_uuid}" ]; then
       ${debug} echo -n "Unplugging VBD: " >&2
-      ${XE} vbd-unplug uuid=${vbd_uuid} timeout=20
+      ${XE} vbd-unplug uuid="${vbd_uuid}" timeout=20
       # poll for the device to go away if we know its name
       if [ "${device}" != "" ]; then
           device_gone=0
           for ((i=0; i<10; i++)); do
               ${debug} echo -n "." >&2
-              if [ ! -b ${device} ]; then
+              if [ ! -b "${device}" ]; then
                   ${debug} echo " done" >&2
                   device_gone=1
                   break
@@ -153,9 +153,9 @@ function cleanup {
           done
           if [ ${device_gone} -eq 0 ]; then
               ${debug} echo " failed" >&2
-              ${debug} echo Please destroy VBD ${vbd_uuid} manually. >&2
+              ${debug} echo "Please destroy VBD ${vbd_uuid} manually." >&2
           else
-              ${XE} vbd-destroy uuid=${vbd_uuid}
+              ${XE} vbd-destroy uuid="${vbd_uuid}"
               vbd_uuid=""
           fi
       fi
@@ -164,7 +164,7 @@ function cleanup {
 }
 
 if [ -z "${vdis}" ]; then
-   echo No VDIs found on SR. >&2
+   echo "No VDIs found on SR." >&2
    exit 0
 fi
 
@@ -173,45 +173,44 @@ trap cleanup SIGINT ERR
 for vdi_uuid in ${vdis}; do
    if [ "${vdi_uuid}" != "${backup_vdi}" ]; then
       echo "Probing VDI ${vdi_uuid}."
-      echo "This VDI was created with a prior version of XenServer."
+      echo "This VDI was created with a prior version of this code."
       echo "Its validity can't be checked without mounting it first."
       read -p "Continue? [Y/N]" -n 1 -r; echo
       if [[ ! $REPLY =~ ^[Yy]$ ]]; then exit 1; fi
    fi
 
    ${debug} echo -n "Creating VBD: " >&2
-   vbd_uuid=$(${XE} vbd-create vm-uuid=${CONTROL_DOMAIN_UUID} vdi-uuid=${vdi_uuid} device=autodetect 2>/dev/null)
+   vbd_uuid=$(${XE} vbd-create vm-uuid="${CONTROL_DOMAIN_UUID}" vdi-uuid="${vdi_uuid}" device=autodetect 2>/dev/null)
 
    if [ $? -ne 0 -o -z "${vbd_uuid}" ]; then
-      ${debug} echo error creating VBD for VDI ${vdi_uuid} >&2
+      ${debug} echo "error creating VBD for VDI ${vdi_uuid}" >&2
       cleanup
       continue
    fi
 
-   ${debug} echo ${vbd_uuid} >&2
+   ${debug} echo "${vbd_uuid}" >&2
 
    ${debug} echo -n "Plugging VBD: " >&2
-   ${XE} vbd-plug uuid=${vbd_uuid}
-   device=/dev/$(${XE} vbd-param-get uuid=${vbd_uuid} param-name=device)
+   ${XE} vbd-plug uuid="${vbd_uuid}"
+   device=/dev/$(${XE} vbd-param-get uuid="${vbd_uuid}" param-name=device)
 
-   if [ ! -b ${device} ]; then
-     ${debug} echo ${device}: not a block special >&2
+   if [ ! -b "${device}" ]; then
+     ${debug} echo "${device}: not a block special" >&2
      cleanup
      continue
    fi
 
-   ${debug} echo ${device} >&2
+   ${debug} echo "${device}" >&2
 
    ${debug} echo -n "Probing device: " >&2
    mnt=
    if [ "$(file_exists "${device}" "/.ctxs-metadata-backup")" = y ]; then
-     ${debug} echo found metadata backup >&2
-     ${debug} echo -n "Mounting filesystem: " >&2
-     mnt=/var/run/pool-backup-${vdi_uuid}
-     mkdir -p ${mnt}
+     ${debug} echo "found metadata backup" >&2
+     mnt="/var/run/pool-backup-${vdi_uuid}"
+     mkdir -p "${mnt}"
      /sbin/e2fsck -p -f "${device}" >/dev/null 2>&1
      if [ $? -ne 0 ]; then
-        echo File system integrity error.  Please correct manually. >&2
+        echo "File system integrity error.  Please correct manually." >&2
         cleanup
         continue
      fi
@@ -221,36 +220,36 @@ for vdi_uuid in ${vdis}; do
        cleanup
      else
        if [ -e "${mnt}/.ctxs-metadata-backup" ]; then
-          ${debug} echo Found backup metadata on VDI: ${vdi_uuid} >&2
-          xe vdi-param-set uuid=${vdi_uuid} other-config:ctxs-pool-backup=true
+          ${debug} echo "Found backup metadata on VDI: ${vdi_uuid}" >&2
+          xe vdi-param-set uuid="${vdi_uuid}" other-config:ctxs-pool-backup=true
           break
        fi
      fi
    else
-     ${debug} echo backup metadata not found >&2
+     ${debug} echo "backup metadata not found" >&2
    fi
    cleanup
 done
 
 if [ $just_probe -gt 0 ]; then
-   echo ${vdi_uuid}
+   echo "${vdi_uuid}"
    cleanup
    exit 0
 fi
 
-cd ${mnt}
+cd "${mnt}"
 ${debug} echo "" >&2
 
-if [ ! -d ${mnt}/metadata ]; then
-   echo Metadata backups not found. >&2
+if [ ! -d "${mnt}/metadata" ]; then
+   echo "Metadata backups not found." >&2
    cleanup
    exit 1
 fi
 
-cd ${mnt}/metadata
+cd "${mnt}/metadata"
 
-if [ $just_list_dates -gt 0 ]; then
-    ls -1r ${mnt}/metadata
+if [ "$just_list_dates" -gt 0 ]; then
+    ls -1r "${mnt}/metadata"
     cleanup
     exit 0
 fi
@@ -258,39 +257,39 @@ fi
 if [ -z "${chosen_date}" ]; then
     chosen_metadata_dir=$(ls | sort -n | tail -1)
     if [ -z "${chosen_metadata_dir}" ]; then
-       echo No VM metadata backups found in ${mnt}/metadata >&2
+       echo "No VM metadata backups found in ${mnt}/metadata" >&2
        cleanup
        exit 1
     fi
 else
-    if [ ! -d ${mnt}/metadata/${chosen_date} ]; then
-       echo Date directory "${chosen_date}" not found >&2
+    if [ ! -d "${mnt}/metadata/${chosen_date}" ]; then
+       echo "Date directory ${chosen_date} not found" >&2
        cleanup
        exit 1
     fi
-    chosen_metadata_dir=${chosen_date}
+    chosen_metadata_dir="${chosen_date}"
 fi
 
 case ${restore_mode} in
 sr)
-    full_dir=${mnt}/metadata/${chosen_metadata_dir}/by-sr/${sr_uuid}
+    full_dir="${mnt}/metadata/${chosen_metadata_dir}/by-sr/${sr_uuid}"
     ;;
 all)
-    full_dir=${mnt}/metadata/${chosen_metadata_dir}/all
+    full_dir="${mnt}/metadata/${chosen_metadata_dir}/all"
     ;;
 esac
 
 if [ ! -d "${full_dir}" ]; then
-    echo No VM metadata exports were found for the selected SR >&2
+    echo "No VM metadata exports were found for the selected SR" >&2
     cleanup
     exit 1
 fi
 
-${debug} echo Selected: ${full_dir}
+${debug} echo "Selected: ${full_dir}"
 
-cd ${full_dir}
+cd "${full_dir}"
 ${debug} echo "" >&2
-${debug} echo Latest VM metadata found is: >&2
+${debug} echo "Latest VM metadata found is": >&2
 ${debug} ls >&2
 
 if [ "$yes" -eq 0 ]; then
@@ -298,14 +297,14 @@ if [ "$yes" -eq 0 ]; then
    echo "Please type in 'yes' and <enter> to continue."
    read response
    if [ "$response" != "yes" ]; then
-     echo Aborting metadata restore.
+     echo "Aborting metadata restore."
      cleanup
      exit 1
    fi
 fi
 
 ${debug} echo "" >&2
-${debug} echo Restoring VM metadata: >&2
+${debug} echo "Restoring VM metadata:" >&2
 
 trap - ERR