Linux kernel issues page

Copying big files causes heavy swapping

Just copying big files on machine with lot of free RAM (8GB) - no big processes. Causes huge swapping activity.

Known reports:

• https://forums.opensuse.org/t/observing-excessive-swapping-when-copying-large-files/138953/19
• https://bugzilla.opensuse.org/show_bug.cgi?id=1159882
• https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1861359

Solutions:

• https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1861359/comments/56

  echo 0 > /proc/sys/vm/watermark_boost_factor
  

  • did not help (tested under Proxmox VE, kernel 6.8.8-2-pve
  • also there:

    echo $((32 * 1024 * 1024)) | sudo tee /proc/sys/vm/dirty_bytes
    echo $((32 * 1024 * 1024)) | sudo tee /proc/sys/vm/dirty_background_bytes
    

• https://forums.opensuse.org/t/observing-excessive-swapping-when-copying-large-files/138953/20

  # sysctl
  vm.swappiness = 10
  vm.vfs_cache_pressure = 5
  

Other related resources:

• https://docs.gluster.org/en/latest/Administrator-Guide/Linux-Kernel-Tuning/