hardware:raspberry_pi:dietpi:zram_swap

DietPi で ZRAM スワップを設定する方法

ZRAM スワップを 476MB に設定する

free コマンドで RAM サイズを調べる🤔

$ free -m

               total        used        free      shared  buff/cache   available
Mem:             477          30         411           1          34         404
Swap:              0           0           0

現在の dietpi-set_swapfile では ZRAM のサイズは RAM サイズ (477MB) -1 の 476MB まで設定できる😉

$ sudo /boot/dietpi/func/dietpi-set_swapfile 476 zram


 DietPi-Set_swapfile
─────────────────────────────────────────────────────
 Mode: Applying 428 zram

[ INFO ] DietPi-Set_swapfile | Disabling and deleting all existing swap files
[  OK  ] DietPi-Set_swapfile | swapoff -a
[  OK  ] DietPi-Set_swapfile | Generating new swap space
[ INFO ] DietPi-Set_swapfile | Size = 476 MiB
[ INFO ] DietPi-Set_swapfile | Path = /dev/zram0
[  OK  ] DietPi-Set_swapfile | eval echo 1 > /sys/block/zram0/reset
[  OK  ] DietPi-Set_swapfile | eval echo '476M' > /sys/block/zram0/disksize
[  OK  ] DietPi-Set_swapfile | chmod 0600 /dev/zram0
[  OK  ] DietPi-Set_swapfile | mkswap /dev/zram0
[  OK  ] DietPi-Set_swapfile | swapon /dev/zram0
[  OK  ] DietPi-Set_swapfile | eval echo 'zram' > /etc/modules-load.d/dietpi-zram-swap.conf
[  OK  ] DietPi-Set_swapfile | eval echo 'SUBSYSTEM=="block", KERNEL=="zram0", ACTION=="add", ATTR{disksize}="476M", RUN+="chmod 0600 /dev/zram0", RUN+="/sbin/mkswap /dev/zram0", RUN+="/sbin/swapon /dev/zram0"' > /etc/udev/rules.d/98-dietpi-zram-swap.rules
[  OK  ] DietPi-Set_swapfile | eval echo 'swappiness=50' > /etc/sysctl.d/98-dietpi-zram-swap.conf
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_SIZE=476
[  OK  ] DietPi-Set_swapfile | Desired setting in /boot/dietpi.txt was already set: AUTO_SETUP_SWAPFILE_LOCATION=zram
[ INFO ] DietPi-Set_swapfile | Setting /tmp tmpfs size: 476 MiB
[  OK  ] DietPi-Set_swapfile | mount -o remount /tmp

ZRAM の他にさらに Swap を 3072MB 追加する

$ sudo fallocate -l 3072M /var/swap
$ sudo chmod 0600 /var/swap
$ sudo mkswap /var/swap

Setting up swapspace version 1, size = 3 GiB (3221221376 bytes)
no label, UUID=9239781e-559a-47a4-b17c-f9f359004181

$ sudo swapon -v /var/swap
$ sudo swapon -s

Filename                                Type            Size    Used    Priority
/dev/zram0                              partition       487420  0       -2
/var/swap                               file            3145724 0       -3

$ free -m

               total        used        free      shared  buff/cache   available
Mem:             477          29         405           1          42         402
Swap:           3499          55        3444

$ echo '/var/swap none swap sw 0 0' | sudo tee -a /etc/fstab

/var/swap none swap sw 0 0

What 'sw' means in the fstab swap entry for 'mount options' column
 Ubuntu日本語フォーラム / swap fileの設定をfstabへの記述するときの設定値の違いについて

通常のスワップファイルを設定する場合

$ sudo /boot/dietpi/func/dietpi-set_swapfile 1 /var/swap


 DietPi-Set_swapfile
─────────────────────────────────────────────────────
 Mode: Applying 1 /var/swap

[ INFO ] DietPi-Set_swapfile | Disabling and deleting all existing swap files
[  OK  ] DietPi-Set_swapfile | swapoff -a
removed '/etc/modules-load.d/dietpi-zram-swap.conf'
removed '/etc/udev/rules.d/98-dietpi-zram-swap.rules'
[  OK  ] DietPi-Set_swapfile | Free space check: path=/var/ | available=104886 MiB | required=1619 MiB
[  OK  ] DietPi-Set_swapfile | Generating new swap space
[ INFO ] DietPi-Set_swapfile | Size = 1619 MiB
[ INFO ] DietPi-Set_swapfile | Path = /var/swap
[  OK  ] DietPi-Set_swapfile | fallocate -l 1619M /var/swap
[  OK  ] DietPi-Set_swapfile | mkswap /var/swap
[  OK  ] DietPi-Set_swapfile | swapon /var/swap
[  OK  ] DietPi-Set_swapfile | chmod 0600 /var/swap
[  OK  ] DietPi-Set_swapfile | eval echo '/var/swap none swap sw' >> /etc/fstab
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_SIZE=1619
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_LOCATION=/var/swap
[ INFO ] DietPi-Set_swapfile | Setting /tmp tmpfs size: 1024 MiB
[  OK  ] DietPi-Set_swapfile | mount -o remount /tmp

通常のスワップファイルを 3GB に設定する場合

$ sudo /boot/dietpi/func/dietpi-set_swapfile 3072 /var/swap


 DietPi-Set_swapfile
─────────────────────────────────────────────────────
 Mode: Applying 3072 /var/swap

[ INFO ] DietPi-Set_swapfile | Disabling and deleting all existing swap files
[  OK  ] DietPi-Set_swapfile | swapoff -a
removed '/var/swap'
[  OK  ] DietPi-Set_swapfile | Free space check: path=/var/ | available=104886 MiB | required=3072 MiB
[  OK  ] DietPi-Set_swapfile | Generating new swap space
[ INFO ] DietPi-Set_swapfile | Size = 3072 MiB
[ INFO ] DietPi-Set_swapfile | Path = /var/swap
[  OK  ] DietPi-Set_swapfile | fallocate -l 3072M /var/swap
[  OK  ] DietPi-Set_swapfile | mkswap /var/swap
[  OK  ] DietPi-Set_swapfile | swapon /var/swap
[  OK  ] DietPi-Set_swapfile | chmod 0600 /var/swap
[  OK  ] DietPi-Set_swapfile | eval echo '/var/swap none swap sw' >> /etc/fstab
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_SIZE=3072
[  OK  ] DietPi-Set_swapfile | Desired setting in /boot/dietpi.txt was already set: AUTO_SETUP_SWAPFILE_LOCATION=/var/swap
[ INFO ] DietPi-Set_swapfile | Setting /tmp tmpfs size: 1750 MiB
[  OK  ] DietPi-Set_swapfile | mount -o remount /tmp

ZRAM スワップを設定する場合

$ sudo /boot/dietpi/func/dietpi-set_swapfile 1 zram


 DietPi-Set_swapfile
─────────────────────────────────────────────────────
 Mode: Applying 1 zram

[ INFO ] DietPi-Set_swapfile | Disabling and deleting all existing swap files
[  OK  ] DietPi-Set_swapfile | swapoff -a
removed '/var/swap'
[  OK  ] DietPi-Set_swapfile | Generating new swap space
[ INFO ] DietPi-Set_swapfile | Size = 214 MiB
[ INFO ] DietPi-Set_swapfile | Path = /dev/zram0
[  OK  ] DietPi-Set_swapfile | eval echo 1 > /sys/block/zram0/reset
[  OK  ] DietPi-Set_swapfile | eval echo '214M' > /sys/block/zram0/disksize
[  OK  ] DietPi-Set_swapfile | chmod 0600 /dev/zram0
[  OK  ] DietPi-Set_swapfile | mkswap /dev/zram0
[  OK  ] DietPi-Set_swapfile | swapon /dev/zram0
[  OK  ] DietPi-Set_swapfile | eval echo 'zram' > /etc/modules-load.d/dietpi-zram-swap.conf
[  OK  ] DietPi-Set_swapfile | eval echo 'SUBSYSTEM=="block", KERNEL=="zram0", ACTION=="add", ATTR{disksize}="214M", RUN+="chmod 0600 /dev/zram0", RUN+="/sbin/mkswap /dev/zram0", RUN+="/sbin/swapon /dev/zram0"' > /etc/udev/rules.d/98-dietpi-zram-swap.rules
[  OK  ] DietPi-Set_swapfile | eval echo 'swappiness=50' > /etc/sysctl.d/98-dietpi-zram-swap.conf
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_SIZE=214
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_LOCATION=zram
[ INFO ] DietPi-Set_swapfile | Setting /tmp tmpfs size: 321 MiB
[  OK  ] DietPi-Set_swapfile | mount -o remount /tmp

ZRAM スワップを 428MB に設定する場合

$ sudo /boot/dietpi/func/dietpi-set_swapfile 428 zram


 DietPi-Set_swapfile
─────────────────────────────────────────────────────
 Mode: Applying 428 zram

[ INFO ] DietPi-Set_swapfile | Disabling and deleting all existing swap files
[  OK  ] DietPi-Set_swapfile | swapoff -a
[  OK  ] DietPi-Set_swapfile | Generating new swap space
[ INFO ] DietPi-Set_swapfile | Size = 428 MiB
[ INFO ] DietPi-Set_swapfile | Path = /dev/zram0
[  OK  ] DietPi-Set_swapfile | eval echo 1 > /sys/block/zram0/reset
[  OK  ] DietPi-Set_swapfile | eval echo '428M' > /sys/block/zram0/disksize
[  OK  ] DietPi-Set_swapfile | chmod 0600 /dev/zram0
[  OK  ] DietPi-Set_swapfile | mkswap /dev/zram0
[  OK  ] DietPi-Set_swapfile | swapon /dev/zram0
[  OK  ] DietPi-Set_swapfile | eval echo 'zram' > /etc/modules-load.d/dietpi-zram-swap.conf
[  OK  ] DietPi-Set_swapfile | eval echo 'SUBSYSTEM=="block", KERNEL=="zram0", ACTION=="add", ATTR{disksize}="428M", RUN+="chmod 0600 /dev/zram0", RUN+="/sbin/mkswap /dev/zram0", RUN+="/sbin/swapon /dev/zram0"' > /etc/udev/rules.d/98-dietpi-zram-swap.rules
[  OK  ] DietPi-Set_swapfile | eval echo 'swappiness=50' > /etc/sysctl.d/98-dietpi-zram-swap.conf
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_SIZE=428
[  OK  ] DietPi-Set_swapfile | Desired setting in /boot/dietpi.txt was already set: AUTO_SETUP_SWAPFILE_LOCATION=zram
[ INFO ] DietPi-Set_swapfile | Setting /tmp tmpfs size: 428 MiB
[  OK  ] DietPi-Set_swapfile | mount -o remount /tmp

ZRAM スワップを 429MB に設定する場合

$ sudo /boot/dietpi/func/dietpi-set_swapfile 429 zram


 DietPi-Set_swapfile
─────────────────────────────────────────────────────
 Mode: Applying 429 zram

[ INFO ] DietPi-Set_swapfile | Disabling and deleting all existing swap files
[  OK  ] DietPi-Set_swapfile | swapoff -a
removed '/etc/modules-load.d/dietpi-zram-swap.conf'
removed '/etc/udev/rules.d/98-dietpi-zram-swap.rules'
[FAILED] DietPi-Set_swapfile | Insufficient RAM size for desired zram-swap size
[ INFO ] DietPi-Set_swapfile | Leaving swap space disabled
[  OK  ] DietPi-Set_swapfile | Setting in /boot/dietpi.txt adjusted: AUTO_SETUP_SWAPFILE_SIZE=0
[  OK  ] DietPi-Set_swapfile | Desired setting in /boot/dietpi.txt was already set: AUTO_SETUP_SWAPFILE_LOCATION=zram
[ INFO ] DietPi-Set_swapfile | Setting /tmp tmpfs size: 214 MiB
[FAILED] DietPi-Set_swapfile | mount -o remount /tmp

free コマンドの RAM サイズ以上を設定出来ない🤔
「Insufficient RAM size for desired zram-swap size」
「必要な zram スワップサイズに対して RAM サイズが不十分です」
と言われる😥確かに RAM は無い😅

# Free spacey, checkey weckey: zram < RAM size
elif [[ $SWAP_FS == 'zram' ]] && (( $(free -m | mawk '/^Mem:/{print $2;exit}') <= $SWAP_SIZE )); then
    Error_Reset 'Insufficient RAM size for desired zram-swap size'
$ free -m
               total        used        free      shared  buff/cache   available
Mem:             429         109          20         233         299          37
Swap:              0           0           0
$ free -m | mawk '/^Mem:/{print $2;exit}'
429

ZRAM にさらに Swap を 3072MB 追加する

$ sudo fallocate -l 3072M /var/swap
$ sudo chmod 0600 /var/swap
$ sudo mkswap /var/swap

Setting up swapspace version 1, size = 3 GiB (3221221376 bytes)
no label, UUID=9239781e-559a-47a4-b17c-f9f359004181

$ sudo swapon /var/swap
$ sudo swapon -s

Filename                                Type            Size    Used    Priority
/dev/zram0                              partition       438268  56152   -2
/var/swap                               file            3145724 0       -3

$ free -m

               total        used        free      shared  buff/cache   available
Mem:             429         141          43         192         244          46
Swap:           3499          55        3444

$ echo '/var/swap none swap sw' | sudo tee -a /etc/fstab

/var/swap none swap sw

再起動すると…😱 zram が優先されない😥

$ sudo reboot
$ sudo swapon -s

Filename                                Type            Size    Used    Priority
/var/swap                               file            3145724 256     -2
/dev/zram0                              partition       438268  0       -3

$ sudo nano /etc/udev/rules.d/98-dietpi-zram-swap.rules


修正前🤔

/etc/udev/rules.d/98-dietpi-zram-swap.rules
SUBSYSTEM=="block", KERNEL=="zram0", ACTION=="add", ATTR{disksize}="428M", RUN+="chmod 0600 /dev/zram0", RUN+="/sbin/mkswap /dev/zram0", RUN+="/sbin/swapon  /dev/zram0"

swapon に priority 100 を指定する🤤 (大きい priority が優先される🤔ここでは 100 の zram0 から優先して使われる😻)

/etc/udev/rules.d/98-dietpi-zram-swap.rules
SUBSYSTEM=="block", KERNEL=="zram0", ACTION=="add", ATTR{disksize}="428M", RUN+="chmod 0600 /dev/zram0", RUN+="/sbin/mkswap /dev/zram0", RUN+="/sbin/swapon -p 100 /dev/zram0"

再起動すると…😱 zram が優先される🥰

$ sudo reboot
$ sudo swapon -s
Filename                                Type            Size    Used    Priority
/var/swap                               file            3145724 0       -2
/dev/zram0                              partition       438268  256     100

dietpi-set_swapfile スクリプトの内容

$ cat /boot/dietpi/func/dietpi-set_swapfile

#!/bin/bash
{
        #////////////////////////////////////
        # DietPi Function: swap file
        #
        #////////////////////////////////////
        # Created by Daniel Knight / daniel.knight@dietpi.com / dietpi.com
        #
        #////////////////////////////////////
        #
        # Info:
        # - Location: /boot/dietpi/func/dietpi-set_swapfile
        # - Allows set the swap file size and path or disable it, based in input arguments, dietpi.txt entry, existing swap file or default, in that priority order.
        #
        # Usage:
        # - <empty>     = this will apply the settings stored in dietpi.txt, refresh the current swap file or apply defaults as fallback
        # - $1          = swap file size [MiB], use "0" to disable or "1" for auto-choice assuring min 2048 MiB total memory, respectively 50% of RAM size when used with "zram"
        # - $2          = swap file path, or use "zram" to create a zram-swap on /dev/zram0 instead
        #////////////////////////////////////
 
        # Import DietPi-Globals --------------------------------------------------------------
        . /boot/dietpi/func/dietpi-globals
        readonly G_PROGRAM_NAME='DietPi-Set_swapfile'
        G_CHECK_ROOT_USER
        G_INIT
        # Import DietPi-Globals --------------------------------------------------------------
 
        EXIT_CODE=0
 
        # Check and apply valid input, else dietpi.txt entry, else current swap file, else revert to defaults
        # - Size
        if disable_error=1 G_CHECK_VALIDINT "$1"; then
 
                SWAP_SIZE=$1
 
        elif ! SWAP_SIZE=$(sed -n '/^[[:blank:]]*AUTO_SETUP_SWAPFILE_SIZE=/{s/^[^=]*=//p;q}' /boot/dietpi.txt) || ! disable_error=1 G_CHECK_VALIDINT "$SWAP_SIZE"; then
 
                SWAP_SIZE=$(mawk '$2=="file" {printf "%.0f",$3/1024;exit}' /proc/swaps) && disable_error=1 G_CHECK_VALIDINT "$SWAP_SIZE" || SWAP_SIZE=1
 
        fi
        # - Path: Store dietpi.txt entry (excluding zram-swap) and active swap files for disabling and removal before creating a new swap space
        SWAP_PATH=$(sed -n '/^[[:blank:]]*AUTO_SETUP_SWAPFILE_LOCATION=/{s/^[^=]*=//p;q}' /boot/dietpi.txt)
        read -ra SWAP_FILES_ACTIVE < <(mawk '$2=="file" {print $1}' /proc/swaps)
        [[ $SWAP_PATH == '/'* && $SWAP_PATH != '/dev/zram0' ]] && SWAP_FILES_ACTIVE+=("$SWAP_PATH")
        if [[ $2 == '/'* || $2 == 'zram' || $2 == 'zram0' ]]; then
 
                SWAP_PATH=$2
 
        elif [[ $SWAP_PATH != '/'* && $SWAP_PATH != 'zram' && $SWAP_PATH != 'zram0' ]]; then
 
                SWAP_PATH=$(mawk '$2=="file" {print $1;exit}' /proc/swaps) && [[ $SWAP_PATH == '/'* || $SWAP_PATH == 'zram' || $SWAP_PATH == 'zram0' ]] || SWAP_PATH='/var/swap'
 
        fi
 
        Update_DietPi_Conf(){
 
                G_CONFIG_INJECT 'AUTO_SETUP_SWAPFILE_SIZE=' "AUTO_SETUP_SWAPFILE_SIZE=$SWAP_SIZE" /boot/dietpi.txt
                [[ $SWAP_FS == 'zram' ]] && SWAP_PATH='zram' # Revert zram path to input value
                G_CONFIG_INJECT 'AUTO_SETUP_SWAPFILE_LOCATION=' "AUTO_SETUP_SWAPFILE_LOCATION=$SWAP_PATH" /boot/dietpi.txt
 
        }
 
        Update_Tmp(){
 
                # Skip if /tmp is not dedicated mount
                grep -q '[[:blank:]]/tmp[[:blank:]]' /etc/fstab || return 0
 
                # Set /tmp to 50% of RAM+SWAP: https://github.com/MichaIng/DietPi/issues/1027#issuecomment-369373082
                local tmp_size=$(( $(free -tm | mawk '/^Total:/{print $2;exit}') / 2 ))
 
                G_DIETPI-NOTIFY 2 "Setting /tmp tmpfs size: $tmp_size MiB"
 
                # Apply to existing fstab entry
                sed -i "/[[:blank:]]\/tmp[[:blank:]]/ctmpfs \/tmp tmpfs size=${tmp_size}M,noatime,lazytime,nodev,nosuid,mode=1777" /etc/fstab
                systemctl daemon-reload
 
                # Apply now to existing mount via "remount" to preserve current content and avoid doubled mount
                [[ $(findmnt -Ufnro FSTYPE -M /tmp) == 'tmpfs' ]] && G_EXEC mount -o remount /tmp
 
        }
 
        Swap_Disable(){
 
                G_DIETPI-NOTIFY 2 'Disabling and deleting all existing swap files'
                (( $G_HW_MODEL == 75 )) || grep -zaq '^container=' /proc/1/environ || G_EXEC swapoff -a
                rm -fv "${SWAP_FILES_ACTIVE[@]}"
                sed -i '/[[:blank:]]swap[[:blank:]]/d' /etc/fstab
                # zram-swap
                [[ -f '/etc/modules-load.d/dietpi-zram-swap.conf' ]] && rm -v /etc/modules-load.d/dietpi-zram-swap.conf
                [[ -f '/etc/udev/rules.d/98-dietpi-zram-swap.rules' ]] && rm -v /etc/udev/rules.d/98-dietpi-zram-swap.rules
 
        }
 
        # Create new swappey whappey
        Swap_Enable(){
 
                G_DIETPI-NOTIFY 0 'Generating new swap space'
                G_DIETPI-NOTIFY 2 "Size = $SWAP_SIZE MiB"
                G_DIETPI-NOTIFY 2 "Path = $SWAP_PATH"
 
                # zram
                if [[ $SWAP_FS == 'zram' ]]; then
 
                        [[ -b $SWAP_PATH ]] || G_EXEC modprobe zram
                        G_EXEC eval 'echo 1 > /sys/block/zram0/reset'
                        G_EXEC eval "echo '${SWAP_SIZE}M' > /sys/block/zram0/disksize"
                        G_EXEC chmod 0600 "$SWAP_PATH"
                        G_EXEC mkswap "$SWAP_PATH"
                        G_EXEC swapon "$SWAP_PATH"
                        # Make persistent, proceed with failure in case of R/O rootfs
                        G_EXEC_NOHALT=1 G_EXEC eval "echo 'zram' > /etc/modules-load.d/dietpi-zram-swap.conf" || return 1
                        G_EXEC_NOHALT=1 G_EXEC eval "echo 'SUBSYSTEM==\"block\", KERNEL==\"zram0\", ACTION==\"add\", ATTR{disksize}=\"${SWAP_SIZE}M\", RUN+=\"chmod 0600 /dev/zram0\", RUN+=\"/sbin/mkswap /dev/zram0\", RUN+=\"/sbin/swapon /dev/zram0\"' > /etc/udev/rules.d/98-dietpi-zram-swap.rules" || return 1
                        G_EXEC_NOHALT=1 G_EXEC eval "echo 'swappiness=50' > /etc/sysctl.d/98-dietpi-zram-swap.conf" || return 1
                        return 0
 
                # Swap file pre-allocation: Try faster and less write-intense fallocate first and dd as fallback
                elif ! G_EXEC_NOHALT=1 G_EXEC fallocate -l "${SWAP_SIZE}M" "$SWAP_PATH" || ! G_EXEC_NOHALT=1 G_EXEC mkswap "$SWAP_PATH" || ! G_EXEC_NOHALT=1 G_EXEC swapon "$SWAP_PATH"; then
 
                        G_DIETPI-NOTIFY 2 'Swap file generation via "fallocate" failed, falling back to "dd"...'
                        G_EXEC swapoff -a
                        G_EXEC dd if=/dev/zero of="$SWAP_PATH" bs=1M "count=$SWAP_SIZE"
                        G_EXEC mkswap "$SWAP_PATH"
                        G_EXEC swapon "$SWAP_PATH"
 
                fi
 
                # Harden permissions, allow to fail on filesystems without UNIX permission support
                G_EXEC_NOHALT=1 G_EXEC chmod 0600 "$SWAP_PATH"
                # Make persistent, proceed with failure in case of R/O rootfs
                G_EXEC_NOHALT=1 G_EXEC eval "echo '$SWAP_PATH none swap sw' >> /etc/fstab" || return 1
 
        }
 
        Error_Reset(){
 
                G_DIETPI-NOTIFY 1 "$*"
                G_DIETPI-NOTIFY 2 'Leaving swap space disabled'
                SWAP_SIZE=0 EXIT_CODE=1
 
        }
 
        #/////////////////////////////////////////////////////////////////////////////////////
        # Main Loop
        #/////////////////////////////////////////////////////////////////////////////////////
        G_DIETPI-NOTIFY 3 "$G_PROGRAM_NAME" "Applying $SWAP_SIZE $SWAP_PATH"
 
        # Always reset existing swap files
        Swap_Disable
 
        # zram-swap
        if [[ $SWAP_PATH == 'zram' || $SWAP_PATH == 'zram0' || $SWAP_PATH == '/dev/zram0' ]]; then
 
                (( $SWAP_SIZE == 1 )) && SWAP_SIZE=$(( $(free -m | mawk '/^Mem:/{print $2;exit}') / 2 )) # Auto size
                SWAP_PATH='/dev/zram0' SWAP_FS='zram'
 
        # swap file
        else
 
                # Auto size: Skip if size would be less than 100 MiB, since else on all 2 GiB SBCs there is a non-reasonable ~50 MiB swap file created
                if (( $SWAP_SIZE == 1 )); then
 
                        SWAP_SIZE=$(( 2048 - $(free -m | mawk '/^Mem:/{print $2;exit}') ))
                        if (( $SWAP_SIZE > 1 && $SWAP_SIZE < 100 )); then
 
                                G_DIETPI-NOTIFY 0 "Skipping the auto-creation of a tiny $SWAP_SIZE MiB swap file"
                                G_DIETPI-NOTIFY 0 'Set < 100 MiB values manually to create such small swap files'
                                SWAP_SIZE=0
 
                        fi
 
                fi
                SWAP_DIR="${SWAP_PATH%/*}/" SWAP_FS=$(findmnt -Ufnro FSTYPE -T "$SWAP_DIR")
 
        fi
 
        # Disable
        if (( $SWAP_SIZE < 1 )); then
 
                SWAP_SIZE=0
 
        # Unsupported in container
        elif (( $G_HW_MODEL == 75 )) || grep -zaq '^container=' /proc/1/environ; then
 
                Error_Reset 'Swap space cannot be controlled form within a container.'
 
        # Unsupported on Btrfs
        elif [[ $SWAP_FS == 'btrfs' ]]; then
 
                Error_Reset 'Swap files are not supported on Btrfs file system.'
 
        # Free spacey, checkey weckey: zram < RAM size
        elif [[ $SWAP_FS == 'zram' ]] && (( $(free -m | mawk '/^Mem:/{print $2;exit}') <= $SWAP_SIZE )); then
 
                Error_Reset 'Insufficient RAM size for desired zram-swap size'
 
        elif [[ $SWAP_FS != 'zram' ]] && ! G_CHECK_FREESPACE "$SWAP_DIR" "$SWAP_SIZE"; then
 
                Error_Reset 'Insufficient free space for desired swap files size'
 
        else
 
                Swap_Enable || EXIT_CODE=1
 
        fi
 
        Update_DietPi_Conf
        Update_Tmp
        #-----------------------------------------------------------------------------------
        exit "$EXIT_CODE"
        #-----------------------------------------------------------------------------------
}
$ sudo apt install git
Reading package lists... Done
Building dependency tree... Done
Reading state information... Done
Suggested packages:
  git-daemon-run | git-daemon-sysvinit git-doc git-el git-email git-gui gitk gitweb git-cvs git-mediawiki git-svn
The following NEW packages will be installed:
  git
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
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Get:1 http://ftp.udx.icscoe.jp/Linux/raspbian/raspbian bullseye/main armhf git armhf 1:2.30.2-1 [4,724 kB]
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debconf: delaying package configuration, since apt-utils is not installed
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Unpacking git (1:2.30.2-1) ...
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$ git clone --depth 1 https://github.com/StuartIanNaylor/zram-swap-config
Cloning into 'zram-swap-config'...
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$ cd zram-swap-config
$ sudo ./install.sh
Created symlink /etc/systemd/system/sysinit.target.wants/zram-swap-config.service → /etc/systemd/system/zram-swap-config.service.
#####     Reboot to activate zram-swap-config     #####
##### edit /etc/zram-swap-config.conf for options #####
$ sudo modprobe zram
$ cat /sys/block/zram0/comp_algorithm
lzo [lzo-rle] lz4 zstd
$ cat /etc/zram-swap-config.conf
# Configuration file for zram-swap-config (https://github.com/StuartIanNaylor/zram-swap-config) under GNU General Public License v3.0 license.
# This configuration file is read by the zram-swap-config service
 
# MEM_FACTOR = Percentage of available ram to allocate to all zram swap devices which is divided equally by swap_devices number
MEM_FACTOR=40
# DRIVE_FACTOR = Virtual uncompressed zram drive size = estimate approx alg compression ratio an results and is the % of the Memfactor
DRIVE_FACTOR=200
# COMP_ALG lz4 is faster than lzo but some distro's show compile and operation difference and in use lzo depending on binary may be faster
COMP_ALG=lzo-rle
# SWAP_DEVICES = number of indivial drives sharing memeory provided by MEM_FACTOR each device support multiple streams 1 large drive is generally better
SWAP_DEVICES=1
# SWAP_PRI = swap_priority for each drive 75 is a hig order preference and should be well above other swap drives
SWAP_PRI=75
# PAGE_CLUSTER default page cluster is 3 which caches fetches in batches of 8 and helps with HDD paging, with zram mem 0 forces single page fetches
# This can help reduce latency and increase performance
PAGE_CLUSTER=0
# SWAPPINESS default swappiness is 60 but with increased performance of zram swap 80 garners overall performance gain without excessive load
# Because zram uses compression load is created and even if minimal at intense load periods such as boot any extra load is unwanted
# Unfortunately there is no dynamic load balancing of swappiness as with zram in general operation SWAPINESS=100 will garner performance benefit
# If the overall load is reasonable at high load it will cause load to accumulate.
SWAPPINESS=90
# If you check my repo there will also be a simple dynamic load branch based SWAPPINESS governor that will get of the hurdle of a static compromise on swappiness
パラメータ 説明
MEM_FACTOR すべての zram スワップデバイスに割り当てるために使用可能な RAM のパーセンテージ。これは、SWAP_DEVICES 番号で均等に除算されます。
DRIVE_FACTOR 仮想非圧縮 zram ドライブサイズ=結果のおおよその alg 圧縮率を見積もり、MEM_FACTOR の % です。
COMP_ALG lz4 は lzo よりも高速ですが、一部のディストリビューションではコンパイルと操作の違いが示され、バイナリによっては lzo の方が高速な場合があります。
SWAP_DEVICES MEM_FACTOR によって提供されるメモリを共有する個々のドライブの数各デバイスは複数のストリームをサポートします 1 つの大きなドライブが一般的に優れています。
SWAP_PRI 各ドライブ 75 の swap_priority は、高位の優先順位であり、他のスワップドライブよりもはるかに高い必要があります。
PAGE_CLUSTER デフォルトのページクラスターは 3 で、フェッチを 8 のバッチでキャッシュし、HDD ページングを支援します。zrammem0 はシングルページフェッチを強制します。
これにより、レイテンシーを削減し、パフォーマンスを向上させることができます。
SWAPPINESS デフォルトの SWAPPINESS は 60 ですが、zram swap 80 のパフォーマンスが向上すると、過度の負荷をかけることなく全体的なパフォーマンスが向上します。
zram は圧縮負荷を使用するため、作成され、ブートなどの激しい負荷期間で最小であっても、余分な負荷は不要です。
残念ながら、一般的な操作で zram を使用する場合のように、SWAPINESS の動的な負荷分散はありません。SWAPINESS=100 はパフォーマンス上の利点をもたらします。
高負荷で全体の負荷が妥当な場合、負荷が蓄積します。

Raspberry Pi 3B (メモリー: 1 GB)

zram-swap-config.conf
MEM_FACTOR=25
DRIVE_FACTOR=300
COMP_ALG=lz4
SWAP_DEVICES=1
SWAP_PRI=75
PAGE_CLUSTER=0
SWAPPINESS=80

Raspberry Pi 4B (メモリー: 1 GB)

zram-swap-config.conf
MEM_FACTOR=10
DRIVE_FACTOR=300
COMP_ALG=lz4
SWAP_DEVICES=1
SWAP_PRI=75
PAGE_CLUSTER=0
SWAPPINESS=80

Raspberry Pi 4B (メモリー: 2 GB)

zram-swap-config.conf
MEM_FACTOR=15
DRIVE_FACTOR=300
COMP_ALG=lz4
SWAP_DEVICES=1
SWAP_PRI=75
PAGE_CLUSTER=0
SWAPPINESS=80
$ sudo systemctl start zram-swap-config
$ sudo systemctl status zram-swap-config

 zram-swap-config.service - zram-swap-config
     Loaded: loaded (/etc/systemd/system/zram-swap-config.service; enabled; vendor preset: enabled)
     Active: active (exited) since Mon 2022-04-18 06:04:20 JST; 14s ago
    Process: 14634 ExecStart=/usr/local/bin/zram-swap-config start (code=exited, status=0/SUCCESS)
   Main PID: 14634 (code=exited, status=0/SUCCESS)
        CPU: 160ms

Apr 18 06:04:19 dietpi-001 zram-swap-config[14636]: modprobe: ERROR: could not insert 'zram': Module already in kernel
Apr 18 06:04:19 dietpi-001 zram-swap-config[14634]: zram1 1
Apr 18 06:04:20 dietpi-001 zram-swap-config[14645]: Setting up swapspace version 1, size = 129 MiB (135225344 bytes)
Apr 18 06:04:20 dietpi-001 zram-swap-config[14645]: no label, UUID=5c52fd2d-6ae3-4e3f-b3fd-484bd1bb8042
Apr 18 06:04:20 dietpi-001 zram-swap-config[14646]: swapon: /dev/zram1: found signature [pagesize=4096, signature=swap]
Apr 18 06:04:20 dietpi-001 zram-swap-config[14646]: swapon: /dev/zram1: pagesize=4096, swapsize=135229440, devsize=1352>
Apr 18 06:04:20 dietpi-001 zram-swap-config[14646]: swapon /dev/zram1
Apr 18 06:04:20 dietpi-001 zram-swap-config[14647]: vm.page-cluster = 0
Apr 18 06:04:20 dietpi-001 zram-swap-config[14648]: vm.swappiness = 80
Apr 18 06:04:20 dietpi-001 systemd[1]: Finished zram-swap-config.

$ sudo zramctl
NAME       ALGORITHM DISKSIZE DATA COMPR TOTAL STREAMS MOUNTPOINT
/dev/zram1 lz4           129M   4K   63B    4K       1 [SWAP]
$ lsblk
NAME        MAJ:MIN RM   SIZE RO TYPE MOUNTPOINT
mmcblk0     179:0    0 116.4G  0 disk
├─mmcblk0p1 179:1    0   128M  0 part /boot
└─mmcblk0p2 179:2    0 116.2G  0 part /
zram1       254:1    0   129M  0 disk [SWAP]
$ sudo swapon --show
NAME       TYPE      SIZE USED PRIO
/var/swap  file      1.6G 1.3M   -2
/dev/zram1 partition 129M   0B   75
  • hardware/raspberry_pi/dietpi/zram_swap.txt
  • 最終更新: 2022/08/10 00:49
  • by ともやん