PostgreSQL 10 High Performance - Third Edition

File access times

Each time you access a file in Linux, a file attribute called the file's last access time (atime) is updated. This overhead turns into a steady stream of writes when you're reading data, which is an unwelcome overhead when working with a database. You can disable this behavior by adding noatime to the volume mount options in /etc/fstab, as in this example:

/dev/sda1 / ext3noatime,errors=remount-ro 0 1  

There are two additional levels of access time updates available in some Linux kernels: nodiratime and relatime, both of which turn off a subset of the atime updates. Both of these are redundant if you use the preferred noatime, which disables them all.