configureDNS

    To expand the default size of 16 GB, locate the `DISK_SIZE` setting in your compose file and modify it to your preferred capacity:

    ```

    ```yaml

    environment:

        DISK_SIZE: "256G"

    ```

    To change the virtual disk's location from the default docker volume, include the following bind mount in your compose file:

    ```

    ```yaml

    volumes:

        - /home/user/data:/storage

    ```

    By default, the entire disk space is reserved in advance. To create a growable disk, that only reserves the space that is actually used, add the following environment variable:

    ```

    ```yaml

    environment:

        ALLOCATE: "N"

    ```

    By default, a single core and 512MB of RAM is allocated to the container. To increase this, add the following environment variables:

    ```

    ```yaml

    environment:

        CPU_CORES: "4"

        RAM_SIZE: "2048M"

    To verify if your system supports KVM, run the following commands:

    ```

    ```bash

    sudo apt install cpu-checker

    sudo kvm-ok

    ```

    If you want to assign an individual IP address to the container, you can create a macvlan network as follows:

    ```

    $ docker network create -d macvlan \

    ```bash

    docker network create -d macvlan \

        --subnet=192.168.0.0/24 \

        --gateway=192.168.0.1 \

        --ip-range=192.168.0.100/28 \

        -o parent=eth0 vdsm

    ```

    Be sure to modify the values to match your local subnet. 

    Be sure to modify these values to match your local subnet. 

    Once you have created the network, modify the container's configuration in your compose file as follows:

    Once you have created the network, change your compose file to make it look as follows:

    ```

    ```yaml

    services:

        dsm:

            container_name: dsm

            ..<snip>..

            networks:

                vdsm:             

                    ipv4_address: 192.168.0.100

    ```

    Finally, add the network to the bottom of your compose file:

    ```

    networks:

        vdsm:

            external: true

    An added benefit of this approach is that you won't have to perform any port mapping anymore, since all ports will be exposed by default.

    Please note that this IP address won't be accessible from the Docker host due to the design of macvlan, which doesn't permit communication between the two. If this is a concern, there are some workarounds available, but they go beyond the scope of this FAQ.

    Please note that this IP address won't be accessible from the Docker host due to the design of macvlan, which doesn't permit communication between the two. If this is a concern, you need to create a [second macvlan](https://blog.oddbit.com/post/2018-03-12-using-docker-macvlan-networks/#host-access) as a workaround.

  * ### How can the container acquire an IP address from my router?

    After configuring the container for macvlan (see above), it will now be able to join your home network by requesting an IP from your router, just like your other devices.

    After configuring the container for macvlan (see above), it is possible for DSM to become part of your home network by requesting an IP from your router, just like your other devices.

    To enable this, add the following lines to your compose file:

    To enable this feature, add the following lines to your compose file:

    ```

    ```yaml

    environment:

        DHCP: "Y"

    devices:

        - /dev/vhost-net

    device_cgroup_rules:

        - 'c 510:* rwm'

        - 'c 511:* rwm'

    ```

    Please note that the exact `cgroup` rule number may vary depending on your system, but the log output will indicate the correct number in case of an error.

    By default version 7.2 will be installed, but if you prefer an older version, you can add its URL to your compose file as follows:

    ```

    ```yaml

    environment:

        URL: "https://global.synologydownload.com/download/DSM/release/7.1.1/42962-1/DSM_VirtualDSM_42962.pat"

    ```

  * ### What are the differences compared to standard DSM?

    There are only three minor differences: the Virtual Machine Manager package is not provided, Surveillance Station doesn't include any free licenses, and logging in to your Synology account is not supported.

    There are only two minor differences: the Virtual Machine Manager package is not provided and Surveillance Station doesn't include any free licenses.

## Disclaimer

  return 0

}

configureDNS () {

  # dnsmasq configuration:

  DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-range=$VM_NET_IP,$VM_NET_IP --dhcp-host=$VM_NET_MAC,,$VM_NET_IP,$VM_NET_HOST,infinite --dhcp-option=option:netmask,255.255.255.0"

  # Create lease file for faster resolve

  echo "0 $VM_NET_MAC $VM_NET_IP $VM_NET_HOST 01:${VM_NET_MAC}" > /var/lib/misc/dnsmasq.leases

  chmod 644 /var/lib/misc/dnsmasq.leases

  # Build DNS options from container /etc/resolv.conf

  if [[ "${DEBUG}" == [Yy1]* ]]; then

    echo "/etc/resolv.conf:" && echo && cat /etc/resolv.conf && echo

  fi

  mapfile -t nameservers < <( { grep '^nameserver' /etc/resolv.conf || true; } | sed 's/\t/ /g' | sed 's/nameserver //' | sed 's/ //g')

  searchdomains=$( { grep '^search' /etc/resolv.conf || true; } | sed 's/\t/ /g' | sed 's/search //' | sed 's/#.*//' | sed 's/\s*$//g' | sed 's/ /,/g')

  domainname=$(echo "$searchdomains" | awk -F"," '{print $1}')

  for nameserver in "${nameservers[@]}"; do

    nameserver=$(echo "$nameserver" | sed 's/#.*//' )

    if ! [[ "$nameserver" =~ .*:.* ]]; then

      [[ -z "$DNS_SERVERS" ]] && DNS_SERVERS="$nameserver" || DNS_SERVERS="$DNS_SERVERS,$nameserver"

    fi

  done

  [[ -z "$DNS_SERVERS" ]] && DNS_SERVERS="1.1.1.1"

  DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:dns-server,$DNS_SERVERS --dhcp-option=option:router,${VM_NET_IP%.*}.1"

  if [ -n "$searchdomains" ] && [ "$searchdomains" != "." ]; then

    DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-search,$searchdomains --dhcp-option=option:domain-name,$domainname"

  else

    [[ -z $(hostname -d) ]] || DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-name,$(hostname -d)"

  fi

  DNSMASQ_OPTS=$(echo "$DNSMASQ_OPTS" | sed 's/\t/ /g' | tr -s ' ' | sed 's/^ *//')

  [[ "${DEBUG}" == [Yy1]* ]] && set -x

  $DNSMASQ ${DNSMASQ_OPTS:+ $DNSMASQ_OPTS}

  { set +x; } 2>/dev/null

  [[ "${DEBUG}" == [Yy1]* ]] && echo

  return 0

}

configureNAT () {

  # Create a bridge with a static IP for the VM guest

    fi

  fi

  # dnsmasq configuration:

  DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-range=$VM_NET_IP,$VM_NET_IP --dhcp-host=$VM_NET_MAC,,$VM_NET_IP,$VM_NET_HOST,infinite --dhcp-option=option:netmask,255.255.255.0"

  # Create lease file for faster resolve

  echo "0 $VM_NET_MAC $VM_NET_IP $VM_NET_HOST 01:${VM_NET_MAC}" > /var/lib/misc/dnsmasq.leases

  chmod 644 /var/lib/misc/dnsmasq.leases

  NET_OPTS="-netdev tap,ifname=${VM_NET_TAP},script=no,downscript=no,id=hostnet0"

  { exec 40>>/dev/vhost-net; rc=$?; } 2>/dev/null || :

  (( rc == 0 )) && NET_OPTS="$NET_OPTS,vhost=on,vhostfd=40"

  # Build DNS options from container /etc/resolv.conf

  if [[ "${DEBUG}" == [Yy1]* ]]; then

    echo "/etc/resolv.conf:" && echo && cat /etc/resolv.conf && echo

  fi

  mapfile -t nameservers < <( { grep '^nameserver' /etc/resolv.conf || true; } | sed 's/\t/ /g' | sed 's/nameserver //' | sed 's/ //g')

  searchdomains=$( { grep '^search' /etc/resolv.conf || true; } | sed 's/\t/ /g' | sed 's/search //' | sed 's/#.*//' | sed 's/\s*$//g' | sed 's/ /,/g')

  domainname=$(echo "$searchdomains" | awk -F"," '{print $1}')

  for nameserver in "${nameservers[@]}"; do

    nameserver=$(echo "$nameserver" | sed 's/#.*//' )

    if ! [[ "$nameserver" =~ .*:.* ]]; then

      [[ -z "$DNS_SERVERS" ]] && DNS_SERVERS="$nameserver" || DNS_SERVERS="$DNS_SERVERS,$nameserver"

    fi

  done

  [[ -z "$DNS_SERVERS" ]] && DNS_SERVERS="1.1.1.1"

  DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:dns-server,$DNS_SERVERS --dhcp-option=option:router,${VM_NET_IP%.*}.1"

  if [ -n "$searchdomains" ] && [ "$searchdomains" != "." ]; then

    DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-search,$searchdomains --dhcp-option=option:domain-name,$domainname"

  else

    [[ -z $(hostname -d) ]] || DNSMASQ_OPTS="$DNSMASQ_OPTS --dhcp-option=option:domain-name,$(hostname -d)"

  fi

  DNSMASQ_OPTS=$(echo "$DNSMASQ_OPTS" | sed 's/\t/ /g' | tr -s ' ' | sed 's/^ *//')

  [[ "${DEBUG}" == [Yy1]* ]] && set -x

  $DNSMASQ ${DNSMASQ_OPTS:+ $DNSMASQ_OPTS}

  { set +x; } 2>/dev/null

  [[ "${DEBUG}" == [Yy1]* ]] && echo

  configureDNS

  return 0

}

#  Configure Network

# ######################################

{ pkill -f server.sh || true; } 2>/dev/null

# Create the necessary file structure for /dev/net/tun

if [ ! -c /dev/net/tun ]; then

  [ ! -d /dev/net ] && mkdir -m 755 /dev/net

if [[ "${DHCP}" == [Yy1]* ]]; then

  if [[ "$GATEWAY" == "172."* ]]; then

    error "You cannot enable DHCP while the container is "

    error "in a bridge network, only on a macvlan network!" && exit 86

    error "You can only enable DHCP while the container is on a macvlan network!" && exit 86

  fi

  # Configuration for DHCP IP

  configureDHCP

  # Display IP on port 80 and 5000

  { pkill -f server.sh || true; } 2>/dev/null

  /run/server.sh 5000 /run/ip.sh &

else