FreeBSD ZFS incremental backup in OVH Cold Archive. zroot snapshots are stored in an encrypted dataset inside the main pool

gistfile1.txt

#!/bin/sh

set -e

# Configuration
zpool="bbox"
snapshot_prefix="${zpool}-"  # Identify your ZPOOL daily snapshots
retention_count=36           # Number of snapshots per container

# Generate snapshot name with date
snapshot_name="${snapshot_prefix}"`date +%Y-%m-%d-%H-%M-%S`

zroot_snapshot_name="zroot-"`date +%Y-%m-%d-%H-%M-%S`
echo "Create zroot@${zroot_snapshot_name}"
zfs snapshot -r zroot@${zroot_snapshot_name}

echo "Start zroot@${zroot_snapshot_name} transfer"
# ZROOT Find the oldest incremental snapshot to base the transfer on
oldest=$(zfs list -t snapshot -o name -r zroot | grep zroot@ | tail -n 2 | head -n 1)
count=$(zfs list -t snapshot -o name -r zroot | grep zroot@ | wc -l)

echo "Oldest snapshot is: ${oldest}"

# Check the existance of a previous older ZROOT snapshot
if [ -n "$oldest" ] && [ "$count" -ge 2 ]; then
	# Do an incremental send
	echo "Start incremental send of zroot@${zroot_snapshot_name} (based on ${oldest})"
	zfs send -Ri ${oldest} zroot@${zroot_snapshot_name} | gzip > /mnt/zroot/${zroot_snapshot_name}.data.gz
else
	# No base snapshot found, do a full send
        echo "Start full send of zroot@${zroot_snapshot_name}"
        zfs send -R zroot@${zroot_snapshot_name} | gzip > /mnt/zroot/${zroot_snapshot_name}.data.gz
fi

echo "Create ${zpool}@${snapshot_name}"
zfs snapshot -r ${zpool}@${snapshot_name}

# ZPOOL Find the oldest incremental snapshot to base the transfer on
oldest=$(zfs list -t snapshot -o name -r ${zpool} | grep ${zpool}@ | tail -n 2 | head -n 1)
count=$(zfs list -t snapshot -o name -r ${zpool} | grep ${zpool}@ | wc -l)

# Check the existance of a previous older ZPOOL snapshot
if [ -n "$oldest" ] && [ "$count" -ge 2 ]; then
    	# Do an incremental send
	echo "Start incremental send of ${zpool}@${snapshot_name} (based on ${oldest})"
	zfs send -Rwi ${oldest} ${zpool}@${snapshot_name} | gzip > /tmp/${snapshot_name}.data.gz
else
        # No base snapshot found, do a full send
        echo "Start full send of ${zpool}@${snapshot_name}"
        zfs send -Rw ${zpool}@${snapshot_name} | gzip > /tmp/${snapshot_name}.data.gz
        echo "Create new OVH Cold Archive Container (bucket: ${snapshot_name})"
        aws --endpoint-url https://s3.rbx-archive.io.cloud.ovh.net --region rbx-archive s3 mb s3://${snapshot_name}
fi


# Upload to Cold Archive
bucket=$(zfs list -t snapshot -o name -r ${zpool} | grep ${zpool}@ | tail -n +1 | head -n 1 | awk -F '@' '{print $2}')
echo "Start copy /tmp/${snapshot_name}.data.gz to OVH Cold Archive ${bucket} container"
rclone copy /tmp/${snapshot_name}.data.gz ovh:${bucket}

# Check for successful upload
if [ $? -eq 0 ]; then
  # Clean up if upload succeeded
  echo "Clean up tmp folder"
  rm /tmp/${snapshot_name}.data.gz
else
  # Exit with a failure status if upload failed
  echo "Upload failed. Exiting script."
  exit 1
fi

# Delete old ZROOT snapshots (beyond the retention count)
old_snapshots=$(zfs list -t snapshot -o name -r zroot | grep zroot@ | tail -n +${retention_count})
if [ -n "$old_snapshots" ]; then
    echo "Deleting old zroot snapshots:"
    echo "$old_snapshots"
    zfs destroy -r $old_snapshots
fi

# Delete old ZPOOL snapshots (beyond the retention count)
old_snapshots=$(zfs list -t snapshot -o name -r ${zpool} | grep ${zpool}@ | tail -n +${retention_count})
if [ -n "$old_snapshots" ]; then
    echo "Archive zfs bucket in OVH Cold Storage"
    aws put-ovh-archive --bucket ${bucket}
    trap 'echo "Cold Archive failed. Exiting..." | mail -s "Cold Archive Error" admin@harmoniis.com; exit 1' EXIT
    echo "Deleting old ${zpool} snapshots:"
    echo "$old_snapshots"
    zfs destroy -r $old_snapshots
fi

echo "Completed"