Home > Workload Solutions > SQL Server > Best Practices > Intel-Based SQL Server Best Practices on Dell PowerEdge R740 and PowerMax 2000 > Linux Best Practices > Performance Best Practices > Red Hat Enterprise Linux: Last Accessed Time (atime)
In this best practice we changed the default Linux disk scheduler per Red Hat guidelines.
Category | Operating System |
Product | Red Hat Enterprise Linux 8.3 |
Type of best practice | Performance Optimization |
Day and value | Day 3, Fine Tuning |
Overview
The Linux operating system tracks the last time a file was accessed, a specification referred to as atime. For example, when the Linux operating system reads data from a data file the access time is updated. Database frequently access data files and updating the access time with each access represents an overhead on the operating system possibly impacting performance.
It is possible to specify no access time (noatime), which means the Linux operating system will not update the access time for files. The goal of this best practice was to reduce associated overhead and increase efficiency by setting the operating system to noatime.
In testing noatime results showed no performance improvements.
Recommendation
Changing the operating system to noatime on database files did not yield performance improvements for any of the following metrics tracked:
The last accessed time recommendation has been a long-standing best practice that might have more value in the past. However, this best practice might have a greater impact on other database systems than our OLTP tests. For this reason, we a recommend the read-ahead best practice as a Day 3, Fine Tuning consideration.
Implementation Steps
To set noatime:
Note: Do these steps and reboot.
References