HP-UX 11i Version 1 Installation and Update Guide, June 2004

Controlling Memory Utilization of VxFS 3.5 on HP-UX 11i v1
Controlling the inode Cache
Appendix E 215
Controlling the inode Cache
As a matter of course, VxFS file systems allocate and free up inodes as
required by the load on the file system. VxFS caches these inodes for
better performance (faster lookups). In general, larger inode caches help
file systems perform better for file/web server loads. The global (static)
tunable vx_ninode, represents the maximum possible size of the VxFS
inode cache. Normally, the size of the inode cache is decided (auto-tuned)
at boot time by VxFS depending on the amount of physical memory in
the machine, provided that the value of vx_ninode is set to zero
(default).
However, system low on RAM (typically less than or equal to 1GB/CPU
may not require a large inode cache if file systems are not exposed to
file/web server loads, or file system performance is not critical. It is
recommended that the value of vx_ninode be set to more than that of
nfile, an HP-UX tunable that represents the maximum number of file
descriptors.