Added File Systems
The following file systems are included in the SunOS release 5.7 directory structure:
The kernel (now called unix) and the kernel modules are stored in the /kernel directory.
The optional /opt file system can be used to store third-party or unbundled software. If /opt is not a separate file system, it may be a symbolic link to /usr/opt.
The /vol file system provides the default file system for the Volume Management daemon, vold(1M). See the volfs(7) man page.