bash script to add zram for rpi

addswap

#!/bin/bash

function addswap {
    SIZE=${1:-2G}
    fallocate -l $SIZE /swapfile
    chmod 600 /swapfile
    mkswap /swapfile
    swapon /swapfile
}

addzram

#!/bin/bash
# run as root: sudo su
# source addzram; addzram 

#set -xe

function delzram {
    swapoff /dev/zram*
    
    for (( i=0; i<$( nproc ); i++)); do
        echo 1 > /sys/block/zram"$i"/reset
    done

    rmmod zram
}

function convert_to_bytes {
    ZRAM_PER_CORE=$(( $( echo $1 | numfmt --from=iec ) / $( nproc ) ))
}

function check_comp_algorithm {
    if grep -qw lz4hc /sys/block/zram0/comp_algorithm; then
        export COMPRESSION_ALGORITHM="lz4hc"
    elif grep -qw lz4 /sys/block/zram0/comp_algorithm; then
        export COMPRESSION_ALGORITHM="lz4"
    elif grep -qw lzo /sys/block/zram0/comp_algorithm; then
        export COMPRESSION_ALGORITHM="lzo"
    elif grep -qw deflate /sys/block/zram0/comp_algorithm; then
        export COMPRESSION_ALGORITHM="deflate"
    else
        echo "No valid compression algorithm found.";
        delzram;
        exit 1;
    fi
}

function get_comp_algorithm {
    if [ -z "$COMPRESSION_ALGORITHM" ]; then
        check_comp_algorithm
    else
        export COMPRESSION_ALGORITHM=$COMPRESSION_ALGORITHM
    fi
}

function addzram {
    swapoff -a
    modprobe zram num_devices=$( nproc )

    TOTAL_ZRAM_SIZE=${1:-4G}

    COMPRESSION_ALGORITHM=$2

    convert_to_bytes $TOTAL_ZRAM_SIZE

    get_comp_algorithm $COMPRESSION_ALGORITHM

    echo 128000 > /proc/sys/vm/min_free_kbytes

    echo 70 > /proc/sys/vm/swappiness

    for (( i=0; i<$( nproc ); i++)); do
        echo "$(( $(nproc) -1))" > /sys/devices/virtual/block/zram"$i"/max_comp_streams
        echo 1 > /sys/block/zram"$i"/reset
        echo $COMPRESSION_ALGORITHM > /sys/block/zram"$i"/comp_algorithm
        echo $ZRAM_PER_CORE > /sys/block/zram"$i"/disksize
        mkswap /dev/zram"$i"
        swapon /dev/zram"$i" -p 10
    done
}

addzswap

#!/bin/bash
# need to be tested
# need to compiled kernel with `CONFIG_ZSWAP`

function addzswap {
    ZSWAP_SIZE={1:-25}
    echo 1 > /sys/module/zswap/parameters/enabled
    echo $ZSWAP_SIZE > /sys/module/zswap/parameters/max_pool_percent
    echo z3fold > /sys/module/zswap/parameters/zpool
    echo lz4 > /sys/module/zswap/parameters/compressor
}

delswap

#!/bin/bash

function delswap {
    swapoff -a
    rm -f /swapfile
}

delzram

#!/bin/bash

function delzram {
    swapoff /dev/zram*
    
    for (( i=0; i<$( nproc ); i++)); do
        echo 1 > /sys/block/zram"$i"/reset
    done

    rmmod zram
}

delzswap

#!/bin/bash
# need to be tested

function delzswap {
    echo 0 > /sys/module/zswap/parameters/enabled
}