Scrub ZFS every N days

freebsd_zfs_scrub_days.sh

#!/bin/sh

# Wait this many days since last scrub
DAYS=30

LANG=C

NOW=$(date -j +%s)
POOLS=$(zpool list -H -o name)

for pool in "$POOLS"
do
  echo "pool: $pool"

  ZPOOLSTATUS=$(/sbin/zpool status $pool)

  if [ $(echo "$ZPOOLSTATUS" | egrep -c "none requested") -ge 1 ]; then
    echo "  ERROR: You need to run \"zpool scrub $pool\" before this script can monitor the scrub expiration time."
    continue
  fi

  if [ $(echo "$ZPOOLSTATUS" | egrep -c "scrub in progress|resilver") -ge 1 ]; then
    echo "  already scrubbing"
    continue
  fi

  # Get last time
  POOLLASTSCRUB=$(echo "$ZPOOLSTATUS" | grep "scan:" | grep "scrub" | rev | cut -f1-4 -d ' ' | rev)

  # convert scrub date to unix time
  LASTSCRUB=$(date -j -f "%b %d %H:%M:%S %Y" "$POOLLASTSCRUB" +%s)
  # Add N days to last time
  NEXTSCRUB=$(date -j -v +${DAYS}d -r "$LASTSCRUB" +%s)

  # compare current time
  if [ "$NOW" -ge "$NEXTSCRUB" ]; then
    echo "  scrubbing"
    /sbin/zpool scrub $pool
  else
    echo "  no need for scrubbing"
  fi

done