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 1.5 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.