from azlux/zram

Zram implementation

README.md

@@ -60,6 +60,17 @@ If you have issue with apache2, you can try to add `apache2.service` next to oth
 
 The log for log2ram will be written at: `/var/log/log2ram.log`
 
+| Compressor name	     | Ratio	| Compression | Decompress. |
+|------------------------|----------|-------------|-------------|
+|zstd 1.3.4 -1	         | 2.877	| 470 MB/s	  | 1380 MB/s   |
+|zlib 1.2.11 -1	         | 2.743    | 110 MB/s    | 400 MB/s    |
+|brotli 1.0.2 -0	     | 2.701	| 410 MB/s	  | 430 MB/s    |
+|quicklz 1.5.0 -1	     | 2.238	| 550 MB/s	  | 710 MB/s    |
+|lzo1x 2.09 -1	         | 2.108	| 650 MB/s	  | 830 MB/s    |
+|lz4 1.8.1	             | 2.101    | 750 MB/s    | 3700 MB/s   |
+|snappy 1.1.4	         | 2.091	| 530 MB/s	  | 1800 MB/s   |
+|lzf 3.6 -1	             | 2.077	| 400 MB/s	  | 860 MB/s    |
+
 ###### Now, muffins for everyone!
 
 

install.sh

@@ -21,4 +21,5 @@ install -m 644 log2ram.logrotate /etc/logrotate.d/log2ram
 # Make sure we start clean
 rm -rf /var/hdd.log
 
-echo "##### Reboot to activate log2ram #####"
+echo "#####         Reboot to activate log2ram         #####"
+echo "##### edit /etc/log2ram.conf to configure options ####"

log2ram

@@ -50,21 +50,44 @@ wait_for () {
     done
 }
 
+createZramLogDrive () {
+	# Check Zram Class created
+	if [ ! -d "/sys/class/zram-control" ]; then
+		modprobe zram
+		RAM_DEV='0'
+	else
+		RAM_DEV=$(cat /sys/class/zram-control/hot_add)
+	fi
+	echo ${COMP_ALG} > /sys/block/zram${RAM_DEV}/comp_algorithm
+	echo ${LOG_DISK_SIZE} > /sys/block/zram${RAM_DEV}/disksize
+	echo ${SIZE} > /sys/block/zram${RAM_DEV}/mem_limit
+	mke2fs -t ext4 /dev/zram${RAM_DEV}
+}
+
 case "$1" in
   start)
       [ -d $HDD_LOG/ ] || mkdir $HDD_LOG/
       mount --bind $RAM_LOG/ $HDD_LOG/
       mount --make-private $HDD_LOG/
       wait_for $HDD_LOG
-      mount -t tmpfs -o nosuid,noexec,nodev,mode=0755,size="$SIZE" log2ram $RAM_LOG/
+	if [ "$ZL2R" = true ]; then
+		createZramLogDrive
+		mount -t ext4 -o nosuid,noexec,nodev,user=log2ram /dev/zram${RAM_DEV} ${RAM_LOG}/
+	else
+		mount -t tmpfs -o nosuid,noexec,nodev,mode=0755,size=${SIZE} log2ram $RAM_LOG/
+	fi
       wait_for $RAM_LOG
       syncFromDisk
       ;;
 
   stop)
       syncToDisk
+	#ZRAM_LOG=$(awk '$2 == "/var/log" {print $1}' /proc/mounts)
+	#ZRAM_LOG=$(echo ${ZRAM_LOG} | grep -o -E '[0-9]+')
       umount -l $RAM_LOG/
       umount -l $HDD_LOG/
+	# Unsure as even with Root permision denied
+	#echo ${ZRAM_LOG} > /sys/class/zram-control/hot_remove
       ;;
 
   write)

log2ram.conf

@@ -14,4 +14,20 @@ USE_RSYNC=false
 
 # If there are some errors with available RAM space, a system mail will be send
 # Change it to false and you will have only a log if there is no place on RAM anymore.
-MAIL=true
+MAIL=true
+
+# **************** Zram backing conf  *************************************************
+
+# ZL2R Zram Log 2 Ram enables a zram drive when ZL2R=true ZL2R=false is mem only tmpfs
+ZL2R=false
+# COMP_ALG this is any compression algorithm listed in /proc/crypto
+# lz4 is fastest with lightest load but deflate (zlib) and Zstandard (zstd) give far better compression ratios
+# lzo is very close to lz4 and may with some binaries have better optimisation
+# COMP_ALG=lz4 for speed or Zstd for compression, lzo or zlib if optimisation or availabilty is a problem
+COMP_ALG=lz4
+# LOG_DISK_SIZE is the uncompressed disk size. Note zram uses about 0.1% of the size of the disk when not in use
+# LOG_DISK_SIZE is expected compression ratio of alg chosen multiplied by log SIZE
+# lzo/lz4=2.1:1 compression ratio zlib=2.7:1 zstandard=2.9:1
+# Really a guestimate of a bit bigger than compression ratio whilst minimising 0.1% mem usage of disk size
+LOG_DISK_SIZE=100M
+

log2ram.service

@@ -1,7 +1,7 @@
 [Unit]
 Description=Log2Ram
 DefaultDependencies=no
-Before=basic.target rsyslog.service syslog.target systemd-journald.service sysinit.target shutdown.target apache2.service
+Before=basic.target rsyslog.service syslog.target systemd-journald.service sysinit.target shutdown.target zram-swap-conf.service apache2.service
 After=local-fs.target
 Conflicts=shutdown.target reboot.target halt.target
 RequiresMountsFor=/var/log /var/hdd.log