HP-UX 11i v3 Installation and Update Guide, February 2007 (Initial Release)

Controlling Memory Utilization of VxFS 4.1 on HP-UX 11i v3
Controlling the inode Cache
Appendix B 151
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 server and 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, systems low on RAM (having typically 1 GB/CPU) may not
require a large inode cache if file systems are not exposed to file server
and web server loads, or when file system performance is not critical. HP
recommends that you set a minimum value as specified below based on
the memory configuration.
NOTE Default values are set at boot time and the values are not automatically
adjusted when memory is added, removed or migrated at run time.
Physical Memory or Kernel
Available Memory
VxFS inode Cache
(number of inodes)
1 GB 16384
2 GB 32768
3 GB 65536
> 3 GB 131072