Move prepare mount steps to beginning

install.sh

@@ -31,6 +31,11 @@ exec 2> >(tee "stderr.log" >&2)
 
 export SNAP_PAC_SKIP=y
 
+umount -R /mnt 2> /dev/null || true
+swapoff --all
+cryptsetup close swap 2> /dev/null || true
+cryptsetup luksClose system 2> /dev/null || true
+
 # Dialog
 BACKTITLE="Arch Linux installation"
 
@@ -114,11 +119,6 @@ echo -e "\n### Setting up fastest mirrors"
 reflector --country 'Germany,France' --protocol https --sort rate --latest 5 --save /etc/pacman.d/mirrorlist
 
 echo -e "\n### Setting up partitions"
-umount -R /mnt 2> /dev/null || true
-swapoff --all
-cryptsetup close swap 2> /dev/null || true
-cryptsetup luksClose luks 2> /dev/null || true
-
 sgdisk --zap-all "${device}"
 sgdisk --clear \
     --new=1:0:+550MiB --typecode=1:ef00 --change-name=1:EFI \