In this best practice we implemented MS-SQL Forced Unit Access (FUA) to improve write performance of the SQL Server database.
FUA is a bit that is sent with writes to storage that improves database performance and durability. FUA was not supported prior to Linux kernel 4.18, which resulted in device level flushing that was inefficient and could impact storage I/O performance. SQL Server addressed storage inefficiency by minimizing flushes, but there was still room for improvement.
Starting with the Linux kernel 4.18, the XFS file systems support the FUA bit. The 4.18 Linux kernel allows the XFS file system and a device supporting FUA writes to avoid the additional block device flush requests. Using the Linux XFS file system and the FUA bit can significantly improve performance for write intensive workloads.
To set the trace flag for writethrough and alternatewritethrough , perform the following steps: