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Afsal
Asked: 2020-05-04 06:39:47 +0800 CST

system slows down after returning from sleep

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I have a 2gb RAM / Atom Z3735F / Ubuntu 20.04 machine . My system slows down after waking up from a sleep . Putting CPU governor in performance mode didn't solve the issue . What i have noticed is after returning from sleep state my swap is almost filled out (1.1G/1.3G) and closing every program reduced the swap usage to 600 mb but it didn't went further down . Any help ?

swapon -show

Filename                                Type            Size    Used    Priority
/swapfile                               file            4194300 780864  -2
/dev/zram0                              partition       524284  524216  100

grep -i swap /etc/fstab

/dev/zram0              none swap sw,pri=32767 0 0
/swapfile    none    swap    defaults,pri=-3      0   0

free -h

              total        used        free      shared  buff/cache   available
Mem:          1.9Gi       1.2Gi        89Mi       316Mi       607Mi       212Mi
Swap:         4.5Gi       1.3Gi       3.2Gi

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enter image description here

swap suspend intel-atom 20.04

2 Answers

  1. Your problem is that you've got a "2gb RAM / Atom Z3735F / Ubuntu 20.04 machine". You should really be running Xubuntu or Lubuntu.

    However, let's try enlarging your swap, and see if it helps.

    If grep -i swap /etc/fstab returns this...

    /swapfile    none    swap    sw      0   0

    Then do this...

    Note: Incorrect use of the dd command can cause data loss. Suggest copy/paste.

    sudo swapoff -a           # turn off swap
sudo rm -i /swapfile      # remove old /swapfile

sudo dd if=/dev/zero of=/swapfile bs=1M count=4096

sudo chmod 600 /swapfile  # set proper file protections
sudo mkswap /swapfile     # init /swapfile
sudo swapon /swapfile     # turn on swap
free -h                   # confirm 2G RAM and 4G swap
reboot                    # reboot and verify operation
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  2. Best Answer

    Let's create a swap file of bigger size : -

    disable swap and remove existing swap file first

    sudo swapoff -a && sudo rm /swapfile

    Start by creating a file which will be used for swap:

    sudo fallocate -l 4G /swapfile
sudo chmod 600 /swapfile
sudo mkswap /swapfile
sudo swapon /swapfile

    To make the change permanent open the /etc/fstab file:

    sudo nano /etc/fstab

    and paste the following line:

    /swapfile swap swap defaults 0 0

    You can also enable zram which will make your low memory system even faster by doing these steps :-

    Open a terminal window and create a new file with the command:

    sudo nano /etc/modules-load.d/zram.conf

    In that file, add the word:

    zram

    Save and close the file.

    Next, create a second new file with the command:

    sudo nano /etc/modprobe.d/zram.conf

    In that file, paste the line:

    options zram num_devices=1

    Save and close the file.

    Next, we need to configure the size of the zRAM partition. Create a new file with the command:

    sudo nano /etc/udev/rules.d/99-zram.rules

    In that file, paste the following (modifying the disksize attribute to fit your needs):

    KERNEL=="zram0", ATTR{disksize}="512M",TAG+="systemd"

    Save and close the file.

    open your fstab file with this command:

    sudo nano /etc/fstab

    and add this line to the bottom:

    /dev/zram0 none swap defaults 0 0

    In order for zRAM to run, we need to create a systemd unit file. Create this file with the command:

    sudo nano /etc/systemd/system/zram.service

    In that file, paste the following contents:

    [Unit]
Description=Swap with zram
After=multi-user.target

[Service]
Type=oneshot 
RemainAfterExit=true
ExecStartPre=/sbin/mkswap /dev/zram0
ExecStart=/sbin/swapon -p 100 /dev/zram0
ExecStop=/sbin/swapoff /dev/zram0

[Install]
WantedBy=multi-user.target

    Save and close the file. Enable the new unit with the command:

    sudo systemctl enable zram

    Reboot the machine.

    For more info refer to this article on techrepublic.com: How to enable the zram module for faster swapping on Linux

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