VERITAS File System 3.5 (HP OnlineJFS/JFS 3.5) Administrator's Guide (August 2003)

Chapter 2
VxFS Performance: Creating, Mounting, and Tuning File Systems
Kernel Tunables
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VxFS Inode Free Time Lag
In VxFS, an inode is put on a freelist if it is not being used. The memory space for this unused inode can be freed it
it stays on the freelist for a specified amount of time. 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 defaultvalue 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.
The following example changes the value of vxfs_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.