Solaris™ Internals: Core Kernel Components

15.6. Directory Name Cache

The directory name cache caches path names for vnodes, so that when we open a file that has been opened recently, we don't need to rescan the directory to find the file name again. Each time we find the path name for a vnode, we store it in the directory name cache. (See “The Directory Name Lookup Cache (DNLC)” for further information on the DNLC operation.) The number of entries in the DNLC is set by the system-tunable parameter, ncsize, which is set at boot time by the calculations shown in Table 15-2. The ncsize parameter is calculated in proportion to the maxusers parameter, which is equal to the number of megabytes of memory installed in the system, capped by a maximum of 1024. The maxusers parameter can also be ...