diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..0c63957
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+ZPOOL_SIZE_SUM_BYTES
diff --git a/README.md b/README.md
index 9102fd2..9b19134 100644
--- a/README.md
+++ b/README.md
@@ -5,6 +5,7 @@ Following settings are made:
 - Disable `pve-enterprise` repo
 - Add `pve-no-subscription` repo
 - Upgrade system to latest version
-- Install basic tools: `vim ifupdown2 net-tools dnsutils ethtool git curl unzip screen iftop lshw smartmontools nvme-cli lsscsi sysstat zfs-auto-snapshot htop mc rpl`
-- Configure snapshot retention for `zfs-auto-snapshot`
-- Set limits for level 1 arc (`zfs_arc_min` and `zfs_arc_max`)
+- Install basic tools: `sudo vim ifupdown2 net-tools dnsutils ethtool git curl unzip screen iftop lshw smartmontools nvme-cli lsscsi sysstat zfs-auto-snapshot htop mc rpl`
+- Configure snapshot retention for `zfs-auto-snapshot` interactively
+- Calculates limits for level 1 arc (`zfs_arc_min` and `zfs_arc_max`) based on all configured zpools
+- Configure backup of `/etc` folder to new zfs dataset on `rpool/pveconf`
diff --git a/install.sh b/install.sh
deleted file mode 100644
index 83cc2a6..0000000
--- a/install.sh
+++ /dev/null
@@ -1,44 +0,0 @@
-#!/bin/bash
-
-# Define basic tools to install
-TOOLS="vim ifupdown2 net-tools dnsutils ethtool git curl unzip screen iftop lshw smartmontools nvme-cli lsscsi sysstat zfs-auto-snapshot htop mc rpl"
-
-# Define zfs-auto-snapshot retention policy
-SNAP_FREQUENT=8
-SNAP_HOURLY=48
-SNAP_DAILY=31
-SNAP_WEEKLY=8
-SNAP_MONTHLY=3
-
-# Define zfs arcsize in Megabytes (MB)
-ZFS_ARC_MIN=128
-ZFS_ARC_MAX=256
-
-# disable pve-enterprise repo and add pve-no-subscription repo
-mv /etc/apt/sources.list.d/pve-enterprise.list /etc/apt/sources.list.d/pve-enterprise.list.bak
-echo "deb http://download.proxmox.com/debian/pve buster pve-no-subscription" > /etc/apt/sources.list.d/pve-no-subscription.list
-apt update
-
-# update system and install basic tools
-DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt -y -qq dist-upgrade
-DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt -y -qq install $TOOLS
-
-# configure zfs-auto-snapshot
-rpl "keep=4" "keep=$SNAP_FREQUENT" /etc/cron.d/zfs-auto-snapshot
-rpl "keep=24" "keep=$SNAP_HOURLY" /etc/cron.hourly/zfs-auto-snapshot
-rpl "keep=31" "keep=$SNAP_DAILY" /etc/cron.hourly/zfs-auto-snapshot
-rpl "keep=8" "keep=$SNAP_WEEKLY" /etc/cron.weekly/zfs-auto-snapshot
-rpl "keep=8" "keep=$SNAP_MONTHLY" /etc/cron.monthly/zfs-auto-snapshot
-
-# set zfs_arc_limits
-ZFS_ARC_MIN_BYTES=$(($ZFS_ARC_MIN*1024*1024))
-ZFS_ARC_MAX_BYTES=$(($ZFS_ARC_MAX*1024*1024))
-
-echo $ZFS_ARC_MIN_BYTES > /sys/module/zfs/parameters/zfs_arc_min
-echo $ZFS_ARC_MAX_BYTES > /sys/module/zfs/parameters/zfs_arc_max
-
-cat << EOF > /etc/modprobe.d/zfs.conf
-options zfs zfs_arc_min=$ZFS_ARC_MIN_BYTES
-options zfs zfs_arc_min=$ZFS_ARC_MAX_BYTES
-EOF
-update-initramfs -u -k all
diff --git a/proxmox-zfs-postinstall.sh b/proxmox-zfs-postinstall.sh
new file mode 100644
index 0000000..6465b2c
--- /dev/null
+++ b/proxmox-zfs-postinstall.sh
@@ -0,0 +1,201 @@
+#!/bin/bash
+
+###### CONFIG SECTION ######
+
+# Define basic tools to install
+TOOLS="sudo vim ifupdown2 net-tools dnsutils ethtool git curl unzip screen iftop lshw smartmontools nvme-cli lsscsi sysstat zfs-auto-snapshot htop mc rpl lsb-release"
+
+#### PVE CONF BACKUP CONFIGURATION ####
+
+# Define target dataset for backup of /etc
+# IMPORTANT NOTE: Don't type in the leading /, this will be set where needed
+PVE_CONF_BACKUP_TARGET=rpool/pveconf
+
+# Define timer for your backup cronjob (default: every 15 minutes fron 3 through 59)
+PVE_CONF_BACKUP_CRON_TIMER="3/15 * * * *"
+
+
+###### SYSTEM INFO AND INTERACTIVE CONFIGURATION SECTION ######
+
+ROUND_FACTOR=512
+
+roundup(){
+    echo $(((($1 + $ROUND_FACTOR) / $ROUND_FACTOR) * $ROUND_FACTOR))
+}
+
+roundoff(){
+    echo $((($1 / $ROUND_FACTOR) * $ROUND_FACTOR))
+}
+
+#### L1ARC SIZE CONFIGURATION ####
+
+# get total size of all zpools
+ZPOOL_SIZE_SUM_BYTES=0
+for line in $(zpool list -o size -Hp); do ZPOOL_SIZE_SUM_BYTES=$(($ZPOOL_SIZE_SUM_BYTES+$line)); done
+
+# get information about available ram
+MEM_TOTAL_BYTES=$(($(awk '/MemTotal/ {print $2}' /proc/meminfo) * 1024))
+
+# get values if defaults are set
+ARC_MAX_DEFAULT_BYTES=$(($MEM_TOTAL_BYTES / 2))
+ARC_MIN_DEFAULT_BYTES=$(($MEM_TOTAL_BYTES / 32))
+
+# get current settings
+ARC_MIN_CUR_BYTES=$(cat /sys/module/zfs/parameters/zfs_arc_min)
+ARC_MAX_CUR_BYTES=$(cat /sys/module/zfs/parameters/zfs_arc_max)
+
+# calculate suggested l1arc sice
+ZFS_ARC_MIN_MEGABYTES=$(roundup $(($ZPOOL_SIZE_SUM_BYTES / 2048 / 1024 / 1024)))
+ZFS_ARC_MAX_MEGABYTES=$(roundoff $(($ZPOOL_SIZE_SUM_BYTES / 1024 / 1024 / 1024)))
+
+echo -e "######## CONFIGURE ZFS L1ARC SIZE ########\n"
+echo "System Summary:"
+echo -e "\tSystem Memory:\t\t$(($MEM_TOTAL_BYTES / 1024 / 1024))\tMB"
+echo -e "\tZpool size (sum):\t$(($ZPOOL_SIZE_SUM_BYTES / 1024 / 1024))\tMB"
+echo -e "Calculated l1arc if set to defaults:"
+if [ $ARC_MIN_DEFAULT_BYTES -lt 33554432 ]; then
+    echo -e "\tDefault zfs_arc_min:\t32\tMB"
+else
+    echo -e "\tDefault zfs_arc_min:\t$(($ARC_MIN_DEFAULT_BYTES / 1024 / 1024))\tMB"
+fi
+echo -e "\tDefault zfs_arc_max:\t$(($ARC_MAX_DEFAULT_BYTES / 1024 / 1024))\tMB"
+echo -e "Current l1arc configuration:"
+if [ $ARC_MIN_CUR_BYTES -gt 0 ]; then
+    echo -e "\tCurrent zfs_arc_min:\t$(($ARC_MIN_CUR_BYTES / 1024 / 1024))\tMB"
+else
+    echo -e "\tCurrent zfs_arc_min:\t0"
+fi
+if [ $ARC_MAX_CUR_BYTES -gt 0 ]; then
+    echo -e "\tCurrent zfs_arc_max:\t$(($ARC_MAX_CUR_BYTES / 1024 / 1024))\tMB"
+else
+    echo -e "\tCurrent zfs_arc_max:\t0"
+fi
+echo -e "Note: If your current values are 0, the calculated values above will apply."
+echo ""
+echo -e "The l1arc cache will be set relative to the size (sum) of your zpools by policy"
+echo -e "zfs_arc_min:\t\t\t$(($ZFS_ARC_MIN_MEGABYTES))\tMB\t\t= 512 MB RAM per 1 TB ZFS storage (round off in 512 MB steps)"
+echo -e "zfs_arc_max:\t\t\t$(($ZFS_ARC_MAX_MEGABYTES))\tMB\t\t= 1 GB RAM per 1 TB ZFS storage (round up in 512 MB steps)"
+echo ""
+RESULT=not_set
+while [ "$(echo $RESULT | awk '{print tolower($0)}')" != "y" ] && [ "$(echo $RESULT | awk '{print tolower($0)}')" != "n" ] && [ "$(echo $RESULT | awk '{print tolower($0)}')" != "" ]; do
+    echo "If you want to apply the values by script policy type 'y', type 'n' to adjust the values yourself [Y/n]?"
+    read
+    RESULT=${REPLY}
+done
+if [[ "$(echo $RESULT | awk '{print tolower($0)}')" == "n" ]]; then
+    echo "Please type in the desired value in MB for 'zfs_arc_min' [$(($ZFS_ARC_MIN_MEGABYTES))]:"
+    read
+    if [[ ${REPLY} -gt 0 ]]; then
+        ZFS_ARC_MIN_MEGABYTES=$((${REPLY}))
+    fi
+    echo "Please type in the desired value in MB for 'zfs_arc_max' [$(($ZFS_ARC_MAX_MEGABYTES))]:"
+    read
+    if [[ ${REPLY} -gt 0 ]]; then
+        ZFS_ARC_MAX_MEGABYTES=$((${REPLY}))
+    fi
+fi
+
+#### SWAPPINESS ####
+
+echo -e "######## CONFIGURE SWAPPINESS ########\n"
+SWAPPINESS=$(cat /proc/sys/vm/swappiness)
+echo "The current swappiness is configured to '$SWAPPINESS %' of free memory until using swap."
+read -p "If you want to change the swappiness, please type in the percentage as number (0 = diasbled):" user_input
+if echo "$user_input" | grep -qE '^[0-9]+$'; then
+    echo "Changing swappiness from '$SWAPPINESS %' to '$user_input %'"
+    SWAPPINESS=$user_input
+else
+    echo "No input - swappiness unchanged at '$SWAPPINESS %'."
+fi
+
+#### ZFS AUTO SNAPSHOT CONFIGURATION ####
+
+# get information about zfs-auto-snapshot and ask for snapshot retention
+declare -A auto_snap_keep=( ["frequent"]="8" ["hourly"]="48" ["daily"]="31" ["weekly"]="8" ["monthly"]="3" )
+dpkg -l zfs-auto-snapshot > /dev/null
+
+if [ $? -eq 0 ]; then
+    echo "'zfs-auto-snapshot' already installed. Reading config..."
+    for interval in "${!auto_snap_keep[@]}"; do
+        if [[ "$interval" == "frequent" ]]; then
+            auto_snap_keep[$interval]=$(cat /etc/cron.d/zfs-auto-snapshot | grep keep | cut -d' ' -f19 | cut -d '=' -f2)
+        else
+            auto_snap_keep[$interval]=$(cat /etc/cron.$interval/zfs-auto-snapshot | grep keep | cut -d' ' -f6 | cut -d'=' -f2)
+        fi
+    done
+else
+    echo "'zfs-auto-snapshot' not installed yet, using script defaults..."
+fi
+echo -e "######## CONFIGURE ZFS AUTO SNAPSHOT ########\n"
+for interval in "${!auto_snap_keep[@]}"; do
+    read -p "Please set how many $interval snapshots to keep (current: keep=${auto_snap_keep[$interval]})" user_input
+    if echo "$user_input" | grep -qE '^[0-9]+$'; then
+        echo "Changing $interval from ${auto_snap_keep[$interval]} to $user_input"
+        auto_snap_keep[$interval]=$user_input
+    else
+        echo "No input - $interval unchanged at ${auto_snap_keep[$interval]}."
+    fi
+done
+
+###### INSTALLER SECTION ######
+
+# disable pve-enterprise repo and add pve-no-subscription repo
+if [[ "$(uname -r)" == *"-pve" ]]; then
+    echo "Deactivating pve-enterprise repository"
+    mv /etc/apt/sources.list.d/pve-enterprise.list /etc/apt/sources.list.d/pve-enterprise.list.bak > /dev/null 2>&1
+    echo "Activating pve-no-subscription repository"
+    echo "deb http://download.proxmox.com/debian/pve buster pve-no-subscription" > /etc/apt/sources.list.d/pve-no-subscription.list
+fi
+echo "Getting latest package lists"
+apt update > /dev/null 2>&1
+
+# update system and install basic tools
+echo "Upgrading system to latest version - Depending on your version this could take a while..."
+DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt -y -qq dist-upgrade > /dev/null 2>&1
+echo "Installing toolset - Depending on your version this could take a while..."
+DEBIAN_FRONTEND=noninteractive DEBIAN_PRIORITY=critical apt -y -qq install $TOOLS > /dev/null 2>&1
+
+# configure zfs-auto-snapshot
+for interval in "${!auto_snap_keep[@]}"; do
+    echo "Setting zfs-auto-snapshot retention: $interval = ${auto_snap_keep[$interval]}"
+    if [[ "$interval" == "frequent" ]]; then
+        CURRENT=$(cat /etc/cron.d/zfs-auto-snapshot | grep keep | cut -d' ' -f19 | cut -d '=' -f2)
+        if [[ "${auto_snap_keep[$interval]}" != "$CURRENT" ]]; then
+            rpl "keep=$CURRENT" "keep=${auto_snap_keep[$interval]}" /etc/cron.d/zfs-auto-snapshot > /dev/null 2>&1
+        fi
+    else
+        CURRENT=$(cat /etc/cron.$interval/zfs-auto-snapshot | grep keep | cut -d' ' -f6 | cut -d'=' -f2)
+        if [[ "${auto_snap_keep[$interval]}" != "$CURRENT" ]]; then
+            rpl "keep=$CURRENT" "keep=${auto_snap_keep[$interval]}" /etc/cron.$interval/zfs-auto-snapshot > /dev/null 2>&1
+        fi
+    fi
+done
+
+echo "Configuring swappiness"
+echo "vm.swappiness=$SWAPPINESS" > /etc/sysctl.d/swappiness.conf
+sysctl -w vm.swappiness=$SWAPPINESS
+
+echo "Configuring pve-conf-backup"
+# create backup jobs of /etc
+zfs list $PVE_CONF_BACKUP_TARGET > /dev/null 2>&1
+if [ $? -ne 0 ]; then
+    zfs create $PVE_CONF_BACKUP_TARGET
+fi
+echo "$PVE_CONF_BACKUP_CRON_TIMER root rsync -va --delete /etc /$PVE_CONF_BACKUP_TARGET > /$PVE_CONF_BACKUP_TARGET/pve-conf-backup.log" > /etc/cron.d/pve-conf-backup
+
+ZFS_ARC_MIN_BYTES=$((ZFS_ARC_MIN_MEGABYTES * 1024 *1024))
+ZFS_ARC_MAX_BYTES=$((ZFS_ARC_MAX_MEGABYTES * 1024 *1024))
+
+echo "Adjusting ZFS level 1 arc"
+echo $ZFS_ARC_MIN_BYTES > /sys/module/zfs/parameters/zfs_arc_min
+echo $ZFS_ARC_MAX_BYTES > /sys/module/zfs/parameters/zfs_arc_max
+
+cat << EOF > /etc/modprobe.d/zfs.conf
+options zfs zfs_arc_min=$ZFS_ARC_MIN_BYTES
+options zfs zfs_arc_min=$ZFS_ARC_MAX_BYTES
+EOF
+
+echo "Updating initramfs - This will take some time..."
+update-initramfs -u -k all > /dev/null 2>&1
+
+echo "Proxmox postinstallation finished!"
\ No newline at end of file