HP JFS 3.3 and HP OnLineJFS 3.3 VERITAS File System 3.3 System Administrator's Guide

118 Chapter6

Application Interface

Get I/O Parameters ioctl

VxFS provides the VX_GET_IOPARAMETERS ioctl to get the recommended

I/O sizes to use on a ﬁle system. This ioctl can be used by the application

to make decisions about the I/O sizes issued to VxFS for a ﬁle or ﬁle

device. For more details on this ioctl, refer to vxfsio(7). For a discussion

on various I/O parameters, refer to Chapter 5 , “Performance and

Tuning,” and vxtunefs (1M).