Monitoring Solaris Volume Manager With a cron Job

How to Automate Checking for Errors in Volumes

• To automatically check your Solaris Volume Manager configuration for errors, create a script that the cron utility can periodically run.

  The following example shows a script that you can adapt and modify for your needs.

  ---

  Note - This script serves as a starting point for automating error checking for Solaris Volume Manager. You probably need to modify this script for your own configuration.

  ---

  #
  #!/bin/ksh
  #ident "@(#)metacheck.sh   1.3     96/06/21 SMI"
  # ident='%Z%%M%   %I%     %E% SMI'
  #
  # Copyright (c) 1999 by Sun Microsystems, Inc.
  #
  # metacheck
  #
  # Check on the status of the metadevice configuration.  If there is a problem
  # return a non zero exit code.  Depending on options, send email notification.
  #
  # -h
  #    help
  # -s setname
  #    Specify the set to check.  By default, the 'local' set will be checked.
  # -m recipient [recipient...]
  #    Send email notification to the specified recipients.  This
  #    must be the last argument. The notification shows up as a short 
  #    email message with a subject of 
  #        "Solaris Volume Manager Problem: metacheck.who.nodename.setname"
  #    which summarizes the problem(s) and tells how to obtain detailed 
  #    information. The "setname" is from the -s option, "who" is from 
  #    the -w option, and "nodename" is reported by uname(1).
  #    Email notification is further affected by the following options:
  #        -f    to suppress additional messages after a problem 
  #            has been found. 
  #        -d    to control the supression.
  #        -w    to identify who generated the email.
  #        -t    to force email even when there is no problem.
  # -w who
  #    indicate who is running the command. By default, this is the
  #    user-name as reported by id(1M). This is used when sending
  #    email notification (-m).
  # -f 
  #    Enable filtering.  Filtering applies to email notification (-m).
  #    Filtering requires root permission.  When sending email notification
  #    the file /etc/lvm/metacheck.setname.pending is used to 
  #    controll the filter.  The following matrix specifies the behavior
  #    of the filter:
  #
  #    problem_found    file_exists
  #      yes          no        Create file, send notification
  #      yes          yes        Resend notification if the current date 
  #                    (as specified by -d datefmt) is 
  #                    different than the file date.
  #      no          yes        Delete file, send notification 
  #                    that the problem is resolved.
  #      no          no        Send notification if -t specified.
  #    
  # -d datefmt
  #    Specify the format of the date for filtering (-f).  This option 
  #    controls the how often re-notification via email occurs. If the 
  #    current date according to the specified format (strftime(3C)) is 
  #    identical to the date contained in the 
  #    /etc/lvm/metacheck.setname.pending file then the message is 
  #    suppressed. The default date format is "%D", which will send one 
  #    re-notification per day.
  # -t
  #    Test mode.  Enable email generation even when there is no problem.
  #    Used for end-to-end verification of the mechanism and email addresses.
  #    
  #
  # These options are designed to allow integration of metacheck
  # into crontab.  For example, a root crontab entry of:
  #
  # 0,15,30,45 * * * * /usr/sbin/metacheck -f -w SVMcron \
  #   -d '\%D \%h' -m [email protected] [email protected]
  #
  # would check for problems every 15 minutes, and generate an email to
  # [email protected] (and send to an email pager service) every hour when 
  # there is a problem.  Note the \ prior to the '%' characters for a 
  # crontab entry.  Bounced email would come back to root@nodename.
  # The subject line for email generated by the above line would be
  # Solaris Volume Manager Problem: metacheck.SVMcron.nodename.local
  #
  
  # display a debug line to controlling terminal (works in pipes)
  decho()
  {
      if [ "$debug" = "yes" ] ; then
      echo "DEBUG: $*"    < /dev/null > /dev/tty 2>&1
      fi
  }
  
  # if string $1 is in $2-* then return $1, else return ""
  strstr()
  {
      typeset    look="$1"
      typeset    ret=""
  
      shift
  #   decho "strstr LOOK .$look. FIRST .$1."
      while [ $# -ne 0 ] ; do
      if [ "$look" = "$1" ] ; then
          ret="$look"
      fi
      shift
      done
      echo "$ret"
  }
  
  # if string $1 is in $2-* then delete it. return result
  strdstr()
  {
      typeset    look="$1"
      typeset    ret=""
  
      shift
  #   decho "strdstr LOOK .$look. FIRST .$1."
      while [ $# -ne 0 ] ; do
      if [ "$look" != "$1" ] ; then
          ret="$ret $1"
      fi
      shift
      done
      echo "$ret"
  }
  
  merge_continued_lines()
  {
      awk -e '\
      BEGIN { line = "";} \
      $NF == "\\" { \
          $NF = ""; \
          line = line $0; \
          next; \
      } \
      $NF != "\\" { \
          if ( line != "" ) { \
          print line $0; \
          line = ""; \
          } else { \
          print $0; \
          } \
      }'
  }
  
  # trim out stuff not associated with metadevices
  find_meta_devices()
  {
      typeset    devices=""
  
  #   decho "find_meta_devices .$*."
      while [ $# -ne 0 ] ; do
      case $1 in
      d+([0-9]) )    # metadevice name
          devices="$devices $1"
          ;;
      esac
      shift
      done
      echo "$devices"
  }
  
  # return the list of top level metadevices
  toplevel()
  {
      typeset    comp_meta_devices=""
      typeset    top_meta_devices=""
      typeset    devices=""
      typeset    device=""
      typeset    comp=""
  
      metastat$setarg -p | merge_continued_lines | while read line ; do
      echo "$line"
      devices=`find_meta_devices $line`
      set -- $devices
      if [ $# -ne 0 ] ; then
          device=$1
          shift
          # check to see if device already refered to as component
          comp=`strstr $device $comp_meta_devices`
          if [ -z $comp ] ; then 
          top_meta_devices="$top_meta_devices $device"
          fi
          # add components to component list, remove from top list
          while [ $# -ne 0 ] ; do
          comp=$1
          comp_meta_devices="$comp_meta_devices $comp"
          top_meta_devices=`strdstr $comp $top_meta_devices`
          shift
          done
      fi
      done > /dev/null 2>&1
      echo $top_meta_devices
  }
  
  #
  # - MAIN
  #
  METAPATH=/usr/sbin
  PATH=//usr/bin:$METAPATH
  USAGE="usage: metacheck [-s setname] [-h] [[-t] [-f [-d datefmt]] \
      [-w who] -m recipient [recipient...]]"
  
  datefmt="%D"
  debug="no"
  filter="no"
  mflag="no"
  set="local"
  setarg=""
  testarg="no"
  who=`id | sed -e 's/^uid=[0-9][0-9]*(//' -e 's/).*//'`
  
  while getopts d:Dfms:tw: flag
  do
      case $flag in
      d)    datefmt=$OPTARG;
      ;;
      D)    debug="yes"
      ;;
      f)    filter="yes"
      ;;
      m)    mflag="yes"
      ;;
      s)    set=$OPTARG;
      if [ "$set" != "local" ] ; then
          setarg=" -s $set";
      fi
      ;;
      t)    testarg="yes";
      ;;
      w)    who=$OPTARG;
      ;;
      \?)    echo $USAGE
      exit 1
      ;;
      esac
  done
  
  # if mflag specified then everything else part of recipient
  shift `expr $OPTIND - 1`
  if [ $mflag = "no" ] ; then
      if [ $# -ne 0 ] ; then 
      echo $USAGE
      exit 1
      fi
  else
      if [ $# -eq 0 ] ; then 
      echo $USAGE
      exit 1
      fi
  fi
  recipients="$*"
  
  curdate_filter=`date +$datefmt`
  curdate=`date`
  node=`uname -n`
  
  # establish files
  msg_f=/tmp/metacheck.msg.$$
  msgs_f=/tmp/metacheck.msgs.$$
  metastat_f=/tmp/metacheck.metastat.$$
  metadb_f=/tmp/metacheck.metadb.$$
  metahs_f=/tmp/metacheck.metahs.$$
  pending_f=/etc/lvm/metacheck.$set.pending 
  files="$metastat_f $metadb_f $metahs_f $msg_f $msgs_f"
  
  rm -f $files                            > /dev/null 2>&1
  trap "rm -f $files > /dev/null 2>&1; exit 1" 1 2 3 15
  
  # Check to see if metadb is capable of running
  have_metadb="yes"
  metadb$setarg                             > $metadb_f 2>&1
  if [ $? -ne 0 ] ; then
      have_metadb="no"
  fi
  grep "there are no existing databases"      < $metadb_f    > /dev/null 2>&1
  if [ $? -eq 0 ] ; then
      have_metadb="no"
  fi
  grep "/dev/md/admin"                < $metadb_f    > /dev/null 2>&1
  if [ $? -eq 0 ] ; then
      have_metadb="no"
  fi
  
  # check for problems accessing metadbs
  retval=0
  if [ "$have_metadb" = "no" ] ; then
      retval=1
      echo "metacheck: metadb problem, can't run '$METAPATH/metadb$setarg'" \
                                  >> $msgs_f
  else
      # snapshot the state
      metadb$setarg 2>&1 | sed -e '1d' | merge_continued_lines    > $metadb_f
      metastat$setarg 2>&1 | merge_continued_lines        > $metastat_f
      metahs$setarg -i 2>&1 | merge_continued_lines        > $metahs_f
  
      #
      # Check replicas for problems, capital letters in the flags
      # indicate an error, fields are seperated by tabs.
      #
      problem=`awk < $metadb_f -F\t '{if ($1 ~ /[A-Z]/) print $1;}'`
      if [ -n "$problem" ] ; then
      retval=`expr $retval + 64`
      echo "\
  metacheck: metadb problem, for more detail run:\n\t$METAPATH/metadb$setarg -i" \
                                  >> $msgs_f
      fi
  
      #
      # Check the metadevice state
      #
      problem=`awk < $metastat_f -e \
          '/State:/ {if ($2 != "Okay" && $2 != "Resyncing") print $0;}'`
      if [ -n "$problem" ] ; then
      retval=`expr $retval + 128`
      echo "\
  metacheck: metadevice problem, for more detail run:" \
                                  >> $msgs_f
  
      # refine the message to toplevel metadevices that have a problem
      top=`toplevel`
      set -- $top
      while [ $# -ne 0 ] ; do
          device=$1
          problem=`metastat $device | awk -e \
          '/State:/ {if ($2 != "Okay" && $2 != "Resyncing") print $0;}'`
          if [ -n "$problem" ] ; then
          echo "\t$METAPATH/metastat$setarg $device"    >> $msgs_f
          # find out what is mounted on the device
          mp=`mount|awk -e '/\/dev\/md\/dsk\/'$device'[ \t]/{print $1;}'`
          if [ -n "$mp" ] ; then
              echo "\t\t$mp mounted on $device"        >> $msgs_f
          fi
          fi
          shift
      done
      fi
  
      #
      # Check the hotspares to see if any have been used.
      #
      problem=""
      grep "no hotspare pools found"    < $metahs_f        > /dev/null 2>&1
      if [ $? -ne 0 ] ; then
      problem=`awk < $metahs_f -e \
          '/blocks/ { if ( $2 != "Available" ) print $0;}'`
      fi
      if [ -n "$problem" ] ; then
      retval=`expr $retval + 256`
      echo "\
  metacheck: hot spare in use, for more detail run:\n\t$METAPATH/metahs$setarg -i" \
                                   >> $msgs_f
      fi
  fi
  
  # If any errors occurred, then mail the report
  if [ $retval -ne 0 ] ; then
      if [ -n "$recipients" ] ; then 
      re=""
      if [ -f $pending_f ] && [ "$filter" = "yes" ] ; then
          re="Re: "
          # we have a pending notification, check date to see if we resend
          penddate_filter=`cat $pending_f | head -1`
          if [ "$curdate_filter" != "$penddate_filter" ] ; then
          rm -f $pending_f                > /dev/null 2>&1
          else
           if [ "$debug" = "yes" ] ; then
              echo "metacheck: email problem notification still pending"
              cat $pending_f
          fi
          fi
      fi
      if [ ! -f $pending_f ] ; then
          if [ "$filter" = "yes" ] ; then
          echo "$curdate_filter\n\tDate:$curdate\n\tTo:$recipients" \
                                  > $pending_f
          fi
          echo "\
  Solaris Volume Manager: $node: metacheck$setarg: Report: $curdate"        >> $msg_f
          echo "\
  --------------------------------------------------------------" >> $msg_f
          cat $msg_f $msgs_f | mailx -s \
          "${re}Solaris Volume Manager Problem: metacheck.$who.$set.$node" $recipients
      fi
      else
      cat $msgs_f
      fi
  else
      # no problems detected,
      if [ -n "$recipients" ] ; then
      # default is to not send any mail, or print anything.
      echo "\
  Solaris Volume Manager: $node: metacheck$setarg: Report: $curdate"        >> $msg_f
      echo "\
  --------------------------------------------------------------" >> $msg_f
      if [ -f $pending_f ] && [ "$filter" = "yes" ] ; then
          # pending filter exista, remove it and send OK
          rm -f $pending_f                    > /dev/null 2>&1
          echo "Problem resolved"                >> $msg_f
          cat $msg_f | mailx -s \
          "Re: Solaris Volume Manager Problem: metacheck.$who.$node.$set" $recipients
      elif [ "$testarg" = "yes" ] ; then
          # for testing, send mail every time even thought there is no problem
          echo "Messaging test, no problems detected"        >> $msg_f
          cat $msg_f | mailx -s \
          "Solaris Volume Manager Problem: metacheck.$who.$node.$set" $recipients
      fi
      else
      echo "metacheck: Okay"
      fi
  fi
  
  rm -f $files                            > /dev/null 2>&1
  exit $retval

  For information on invoking scripts by using the cron utility, see the cron(1M) man page.