diff --git a/Makefile b/Makefile
index fea5e91..f86e94a 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,7 @@
 #!/usr/bin/make -f
+# Change the default shell /bin/sh which does not implement 'source'
+# source is needed to work in a python virtualenv
+SHELL := /bin/bash
 
 # remove 'download_extra' to build without third party software/dotfiles
 all: install_buildenv clean download_extra build
@@ -19,7 +22,7 @@ clean:
 
 bump_version:
 	@last_tag=$$(git tag | tail -n1); \
-	echo "Please set version to $$last_tag in Makefile config/bootloaders/isolinux/live.cfg.in config/bootloaders/isolinux/menu.cfg auto/config"
+	echo "Please set version to $$last_tag in Makefile config/bootloaders/isolinux/live.cfg.in config/bootloaders/isolinux/menu.cfg auto/config doc/md/download-and-installation.md"
 
 build:
 	# Build the live system/ISO image
@@ -51,7 +54,14 @@ release_archive:
 
 ################################
 
-tests: download_iso test_kvm_bios test_kvm_uefi
+tests: test_imagesize download_iso test_kvm_bios test_kvm_uefi
+
+test_imagesize:
+	@size=$$(du -b iso/*.iso | cut -f 1); \
+	echo "[INFO] ISO image size: $$size bytes"; \
+	if [[ "$$size" -gt 2147483648 ]]; then \
+		echo '[WARNING] ISO image size is larger than 2GB!'; \
+	fi
 
 download_iso:
 	# download the iso image from a build server
@@ -59,7 +69,7 @@ download_iso:
 
 test_kvm_bios:
 	# Run the resulting image in KVM/virt-manager (legacy BIOS mode)
-	sudo virt-install --name dlc-test --boot cdrom --disk path=/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2-debian-buster-amd64.hybrid.iso' --memory 2048 --vcpu 2
+	sudo virt-install --name dlc-test --boot cdrom --disk path=/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2.2-debian-buster-amd64.hybrid.iso' --memory 2048 --vcpu 2
 	sudo virsh destroy dlc-test
 	sudo virsh undefine dlc-test
 	sudo rm /dlc-test-disk0.qcow2
@@ -67,7 +77,7 @@ test_kvm_bios:
 test_kvm_uefi:
 	# Run the resulting image in KVM/virt-manager (UEFI mode)
 	# UEFI support must be enabled in QEMU config for EFI install tests https://wiki.archlinux.org/index.php/Libvirt#UEFI_Support (/usr/share/OVMF/*.fd)
-	sudo virt-install --name dlc-test --boot loader=/usr/share/OVMF/OVMF_CODE.fd --disk path=/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2-debian-buster-amd64.hybrid.iso' --memory 2048 --vcpu 2
+	sudo virt-install --name dlc-test --boot loader=/usr/share/OVMF/OVMF_CODE.fd --disk path=/dlc-test-disk0.qcow2,format=qcow2,size=20,device=disk,bus=virtio,cache=none --cdrom 'iso/dlc-2.2.2-debian-buster-amd64.hybrid.iso' --memory 2048 --vcpu 2
 	sudo virsh destroy dlc-test
 	sudo virsh undefine dlc-test
 	sudo rm /dlc-test-disk0.qcow2
@@ -79,7 +89,7 @@ test_kvm_uefi:
 #               gitea-cli config defined in ~/.config/gitearc
 update_todo:
 	git clone https://github.com/bashup/gitea-cli gitea-cli
-	-rm TODO.md
-	echo '<!-- This file is automatically generated by "make update_todo" -->' > TODO.md
-	./gitea-cli/bin/gitea issues zerodb/debian-live-config | jq -r '.[] | "- #\(.number) - \(.title)"' >> TODO.md; \
+	-rm doc/md/TODO.md
+	echo '<!-- This file is automatically generated by "make update_todo" -->' > doc/md/TODO.md
+	./gitea-cli/bin/gitea issues zerodb/debian-live-config | jq -r '.[] | "- #\(.number) - \(.title)"' >> doc/md/TODO.md; \
 	rm -rf gitea-cli