Windows 2000 Read-Only
File System
Another use of parent-child disk chaining is to create read-only access for Windows 2000, which has no option for mounting a read-only file system.
In Attaching Virtual Read/Write Disk for Windows 2000, the gray circle represents a virtual disk that must remain read-only because it has children. In this example, you want the Windows 2000 virtual machine to use that virtual disk, rather than the newer ones C1 and C2. Create new child disk RO, attach to the gray virtual disk as parent, and mount RO as the (mostly empty) read-only virtual disk of the Windows 2000 guest OS.
