When a system is upgraded from IIS 3.0 or earlier to IIS 4.0, the configuration parameters that were previously set in the registry are migrated to the metabase. When IIS starts, it loads the metabase into memory, where it is available until IIS shuts down. The metabase is stored in a special format file by default named Metabase.bin in the Inetsrv folder in which IIS is normally installed.
Like the registry, the metabase is organized in a hierarchical structure that mirrors the structure of your IIS installation. It is made up of nodes, keys, and subkeys. The main organization is by node, with each node in the metabase structure representing a site or directory. Beneath the nodes are keys that may contain one or more IIS configuration values called metabase properties. The metabase keys correspond to individual configuration elements of IIS; each key contains properties that affect the configuration of its associated directory or site.
The structure of the metabase facilitates different settings of a property for different nodes. For example, the MaxBandwidth property setting can be different for each virtual site. However, metabase properties are inherited. This means that those parameters that are configured at higher levels, such as the Web site level, will affect the lower levels. But if you set a specific property for an individual site, virtual site, or virtual directory, changes made at a higher level will not automatically override the lower-level individual setting. Note that when the metabase is searched for configuration information, it is enumerated from the bottom, or subkey, to top, or node.
Many of the metabase parameters can be configured from the Internet Service Manager snap-in for the Microsoft Management Console (MMC). Additional tools are also available for further tuning of the metabase.
CautionConfiguring properties in the metabase incorrectly can cause problems, including the failure of a Web site or FTP site. If you make mistakes, your Web site or FTP site's configuration could be damaged. You should edit metabase properties only for settings that you cannot adjust in the user interface. Be very careful whenever you edit the metabase directly.
There are two main ways to edit the metabase:
- IIS Administration Script Utility (Adsutil): Adsutil.vbs is a Visual Basic Script utility that uses Active Directory Service Interfaces (ADSI) to manipulate the configuration of IIS. Run this script using CScript, which is installed with the Windows Scripting Host as part of the Windows NT Option Pack. Cscript.exe is installed to %system root%/System32. Adsutil.vbs is installed to %system root$/System32/Inetsrv/Adminsamples.
- Mdutil.exe: This utility is available on the Option Pack CD-ROM. It can be utilized from: \Ntoppak\En\X86\Winnt.srv\Mdutil.exe.