add ZRAM (#3102)

CHANGES.md

@@ -4,6 +4,7 @@
 
 - New: WebUI
 - New: BackendAPI
+- New: ZRAM - compressed swap in memory [details](https://github.com/rootzoll/raspiblitz/issues/2905)
 - New: Core Lightning GRPC plugin [details](https://github.com/rootzoll/raspiblitz/pull/3109)
 - Update: Bitcoin Core v23.0 [details](https://github.com/bitcoin/bitcoin/blob/master/doc/release-notes/release-notes-23.0.md)
 - Update: Core Lightning (CLN - formerly C-lightning) v0.11.0.1 [details](https://github.com/ElementsProject/lightning/releases/tag/v0.11.0.1)

home.admin/_provision_.sh

@@ -66,7 +66,7 @@ echo "deprecatedrpc=addresses" >> /mnt/hdd/bitcoin/bitcoin.conf 2>/dev/null
 # backup SSH PubKeys
 /home/admin/config.scripts/blitz.ssh.sh backup
 
-# optimze mempool if RAM >1GB
+# optimize mempool if RAM >1GB
 kbSizeRAM=$(cat /proc/meminfo | grep "MemTotal" | sed 's/[^0-9]*//g')
 if [ ${kbSizeRAM} -gt 1500000 ]; then
   echo "Detected RAM >1GB --> optimizing ${network}.conf"
@@ -77,6 +77,9 @@ if [ ${kbSizeRAM} -gt 3500000 ]; then
   sed -i "s/^maxmempool=.*/maxmempool=300/g" /mnt/hdd/${network}/${network}.conf
 fi
 
+# zram on for all devices
+/home/admin/config.scripts/blitz.zram.sh on
+
 # link and copy HDD content into new OS on sd card
 echo "Copy HDD content for user admin" >> ${logFile}
 mkdir /home/admin/.${network} >> ${logFile} 2>&1

home.admin/config.scripts/blitz.zram.sh

@@ -0,0 +1,60 @@
+#!/bin/bash
+
+# using https://github.com/foundObjects/zram-swap
+VERSION="205ea1ec5b169f566e5e98ead794e9daf90cf245"
+
+# command info
+if [ $# -eq 0 ] || [ "$1" = "-h" ] || [ "$1" = "-help" ]; then
+  echo "config script to install ZRAM"
+  echo "blitz.zram.sh [on|off]"
+  echo "using https://github.com/foundObjects/zram-swap"
+  exit 1
+fi
+
+mkdir /home/admin/download 2>/dev/null
+cd /home/admin/download || exit 1
+if [ ! -d zram-swap ]; then
+  sudo -u admin git clone https://github.com/foundObjects/zram-swap.git
+  cd zram-swap || exit 1
+  git reset --hard $VERSION || exit 1
+else
+  cd zram-swap || exit 1
+fi
+
+if [ "$1" = on ]; then
+  if [ $(sudo cat /proc/swaps | grep -c zram) -eq 0 ]; then
+    # install zram to 1/2 of RAM, activate and prioritize
+    sudo /home/admin/download/zram-swap/install.sh
+
+    # make better use of zram
+    echo "\
+vm.vfs_cache_pressure=500
+vm.swappiness=100
+vm.dirty_background_ratio=1
+vm.dirty_ratio=50
+" | sudo tee -a  /etc/sysctl.conf
+
+    # apply
+    sudo sysctl --system
+    echo "# ZRAM is installed and activated"
+  else
+    echo "# ZRAM was already installed and active."
+  fi
+
+  echo "Current swap usage:"
+  sudo cat /proc/swaps
+  exit 0
+fi
+
+if [ "$1" = off ]; then
+  sudo /home/admin/download/zram-swap/install.sh --uninstall
+  sudo rm /etc/default/zram-swap
+  sudo rm -rf /home/admin/download/zram-swap
+  echo "ZRAM was removed"
+  echo "Current swap usage:"
+  sudo cat /proc/swaps
+  exit 0
+fi
+
+echo "FAIL - Unknown Parameter $1"
+exit 1

home.admin/config.scripts/bonus.fulcrum.sh

@@ -30,8 +30,8 @@ if [ "$1" = on ]; then
   # ?wait until txindex finishes?
   /home/admin/config.scripts/network.txindex.sh on
 
-  # ?activate zram?
-  # https://github.com/rootzoll/raspiblitz/issues/2905
+  # activate zram
+  /home/admin/config.scripts/blitz.zram.sh on
 
   # rpcworkqueue=512
   # rpcthreads=128
@@ -115,7 +115,7 @@ db_mem=1024
 db_max_open_files=200
 fast-sync = 1024
 
-# for 8GB RAM
+# for 8GB RAM - use settings as for 4GB
 #db_max_open_files=500
 #fast-sync = 2048