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About enhanced I/O performance

VxFS provides enhanced I/O performance by applying an aggressive I/O clustering policy, integrating with VxVM, and allowing application specific parameters to be set on a per-file system basis.

About enhanced I/O clustering

I/O clustering is a technique of grouping multiple I/O operations together for improved performance. VxFS I/O policies provide more aggressive clustering processes than other file systems and offer higher I/O throughput when using large files. The resulting performance is comparable to that provided by raw disk.

About VxVM integration

VxFS interfaces with VxVM to determine the I/O characteristics of the underlying volume and perform I/O accordingly. VxFS also uses this information when using mkfs to perform proper allocation unit alignments for efficient I/O operations from the kernel.

As part of VxFS/VxVM integration, VxVM exports a set of I/O parameters to achieve better I/O performance. This interface can enhance performance for different volume configurations such as RAID-5, striped, and mirrored volumes. Full stripe writes are important in a RAID-5 volume for strong I/O performance. VxFS uses these parameters to issue appropriate I/O requests to VxVM.

About application-specific parameters

You can also set application specific parameters on a per-file system basis to improve I/O performance.

• Discovered Direct I/O

  All sizes above this value would be performed as direct I/O.

• Maximum Direct I/O Size

  This value defines the maximum size of a single direct I/O.

See VxFS performance: creating, mounting, and tuning File Systems.

See the vxtunefs(1M) and tunefstab(4) manual pages.