#!/bin/bash

# Author: Alan J. Pippin
# Description: This script will attempt to scrub a given pool.
#              This script ensures that only 1 scrub operation is 
#              running at any given time. This serializes the zfs 
#              scrub process for any pool.

# source our configuration
config="${0%/*}/zfs-scripts.conf"
[ -e "${config}.dist" ] && . ${config}.dist
[ -e "${config}" ] && . ${config}

exec >> $logdir/zfs-scrub.log 2>&1

pools="$*"
maxsleeptime=360

if [ -z "$pools" ]; then
   echo "-E- Usage: $0 <pools>"
   exit 1
fi

for i in $pools
do
  # Check to see if any zfs filesystem has a scrub being performed on it now.
  # If it does, we cannot perform more than one scrub operation at a time.
  while true; do
    zpool status | grep scrub: | grep "in progress" > /dev/null 2>&1
    if [ $? == 0 ]; then
        # Another zpool scrub operation is already running
        # Wait until it is done before continuing
        ransleep=$(($RANDOM % $maxsleeptime))
        sleep $ransleep
    else
        # Another zpool scrub operation is not running
        break
    fi
  done

  date=`date`
  echo "$date: Scrub started for zfs pool $i"
  zpool scrub $i

  # Wait until the scrub completes, and check for any errors
  while true; do
    zpool status $i | grep scrub: | grep "in progress" > /dev/null 2>&1
    if [ $? == 0 ]; then
        # Our zpool scrub operation is still running
        # Wait until it is done before continuing
        ransleep=$(($RANDOM % $maxsleeptime))
        sleep $ransleep
    else
        # Our scrub operation has completed
        break
    fi
  done

  date=`date`
  echo "$date: Scrub completed for zfs pool $i"

  # Check for any scrub errors
  zpool status $i | grep scrub: | grep "with 0 errors" > /dev/null 2>&1
  if [ $? != 0 ]; then
    # The scrub found errors
    zpool status $i | $mailx -s "zpool scrub $i found errors" $mailto 
  fi 

done