Fix swapfile

Snapshots won't work on swapfile containing subvolume, best to move it to it's own

0-preinstall.sh

@@ -177,16 +177,18 @@ echo -ne "
 "
 TOTALMEM=$(cat /proc/meminfo | grep -i 'memtotal' | grep -o '[[:digit:]]*')
 if [[  $TOTALMEM -lt 8000000 ]]; then
-    #Put swap into the actual system, not into RAM disk, otherwise there is no point in it, it'll cache RAM into RAM. So, /mnt/ everything.
-    mkdir /mnt/opt/swap #make a dir that we can apply NOCOW to to make it btrfs-friendly.
-    chattr +C /mnt/opt/swap #apply NOCOW, btrfs needs that.
-    dd if=/dev/zero of=/mnt/opt/swap/swapfile bs=1M count=2048 status=progress
-    chmod 600 /mnt/opt/swap/swapfile #set permissions.
-    chown root /mnt/opt/swap/swapfile
-    mkswap /mnt/opt/swap/swapfile
-    swapon /mnt/opt/swap/swapfile
-    #The line below is written to /mnt/ but doesn't contain /mnt/, since it's just / for the sysytem itself.
-    echo "/opt/swap/swapfile	none	swap	sw	0	0" >> /mnt/etc/fstab #Add swap to fstab, so it KEEPS working after installation.
+    # Put swapfile into separate subvolume or else you wouldn't be able to make snapshots of root
+    btrfs subvolume create /mnt/swap
+    truncate -s 0 /mnt/swap/swapfile
+    chattr +C /mnt/swap/swapfile #apply NOCOW, btrfs needs that.
+    btrfs property set /mnt/swap/swapfile compression none
+    dd if=/dev/zero of=/mnt/swap/swapfile bs=1M count=4096 status=progress
+    chmod 600 /mnt/swap/swapfile #set permissions.
+    chown root /mnt/swap/swapfile
+    mkswap /mnt/swap/swapfile
+    swapon /mnt/swap/swapfile
+    echo "/swap/swapfile	none	swap	sw	0	0" >> /mnt/etc/fstab #Add swap to fstab, so it KEEPS working after installation.
+    echo "vm.swappiness=10" >> /mnt/etc/sysctl.conf # Lower swappiness
 fi
 echo -ne "
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