The effectiveness of the system's namei caches can be seen using sar -n:
23:59:44 c_hits cmisses (hit %) 23:59:49 869 0 (100%) 23:59:54 1091 6 ( 99%) 23:59:59 832 0 (100%)
Average 931 2 (100%)
c_hitsindicates the number of pathname components that were found in the namei cache.
cmisses indicates the number of pathname
components that were not found in the namei cache and
subsequently required that the information be read from one
of the disk drives.
hit % gives the percentage of the
total number of pathname components
referenced that were found in the namei cache.
See ``Reducing disk I/O by increasing the size of the namei cache'' for more information about tuning the namei cache.