VERITAS File System 4.1 Administrator's Guide

VxFS Performance: Creating, Mounting, and Tuning File Systems
Kernel Tunables
Chapter 254
The vxfs_ifree_timelag tunable specifies the minimum amount of time an unused inode
spends on a freelist before its memory space is freed.vxfs_ifree_timelag is a dynamic
tunable. Any changes to vxfs_ifree_timelag take affect immediately.
The default value of vxfs_ifree_timelag is 0. By setting vxfs_ifree_timelag to 0, the
inode free timelag is autotuned to 1800 seconds. Specifying negative one (–1) stops the freeing
of inode space; no further inode allocations are freed until the value is changed back to a value
other than negative one.
You can change the value of vx_ifree_timelag using the sam or kctune commands (see the
sam(1M) and kctune(1M) manual pages), or by adding an entry to the system configuration
file. The following example changes the value of vx_ifree_timelag to 2400 seconds:
# kctune –s vxfs_ifree_timelag=2400
NOTE The default value vxfs_ifree_timelag typically provides optimal VxFS
performance. Be careful when adjusting the tunable because incorrect tuning
can adversely affect system performance.