Disk Optimizations

General

Reducing disk I/O on SD and MMC class storage devices can significantly extend their lifetime.

You can monitor per-process disk IO with sudo iotop -oPa

journald

systemd journald logging contributes to a significant amount of disk I/O. Changing the storage to volatile only logs to memory. This can result in an 80% reduction of IOs on a standard all sky system.

sudo mkdir /etc/systemd/journald.conf.d

sudo tee /etc/systemd/journald.conf.d/90-indi-allsky.conf <<EOF
[Journal]
Storage=volatile
Compress=yes
RateLimitIntervalSec=30s
RateLimitBurst=10000
SystemMaxUse=20M
EOF

sudo systemctl restart systemd-journald 

ext4 commit interval

Add commit=300 to the mount options for the filesystems.

• File: /etc/fstab

    UUID=abcdabcd-1234-4c97-1234-181c2d402646   /   ext4    defaults,noatime,commit=300 0   1
  

Decrease swappiness

This will decrease the rate at which the Linux kernel will swap out memory pages to the swap file and reduce disk I/O.

echo "vm.swappiness = 1" | sudo tee /etc/sysctl.d/90-indi-allsky.conf

sudo sysctl --system

tmpfs

Utilize a memory backed filesystem for /tmp to reduce writes

# /etc/fstab
...
tmpfs /tmp tmpfs defaults,nosuid,size=512m 0 0
...