PostgreSQL 12 High Availability Cookbook - Third Edition

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There is one final important mount option that we have not yet discussed—nobarrier. Write barriers insert a flush operation between a filesystem write and disk sync to prevent inadvertent data reordering. Some storage devices contain a battery-backed disk cache such as high-end RAID solutions, SANs, and some solid-state disks with on-board capacitors. This kind of hardware can survive sudden power loss and does not require explicit barrier-imposed data flushing.

Without this excessive data flushing, write performance can improve noticeably. To use this setting, merely include nobarrier in the list of mount options; for example, consider the following:

mount -t xfs -o noatime,nodiratime,logbsize=256k \
 -o allocsize=1m,nobarrier ...