VxVM and the Operating System

VxVM operates as a subsystem between your operating system and your data management systems, such as file systems and database management systems. VxVM is tightly coupled with the operating system. Before a disk can be brought under VxVM control, the disk must be accessible through the operating system device interface. VxVM is layered on top of the operating system interface services, and is dependent upon how the operating system accesses physical disks.

VxVM is dependent upon the operating system for the following functionality:

• operating system (disk) devices
• device handles
• VxVM dynamic multipathing (DMP) metadevice

This guide introduces you to the VxVM commands which are used to carry out the tasks associated with VxVM objects. These commands are described on the relevant manual pages and in the chapters of this guide where VxVM tasks are described.

VxVM relies on the following constantly running daemons for its operation:

• vxconfigd---The VxVM configuration daemon maintains disk and group configurations and communicates configuration changes to the kernel, and modifies configuration information stored on disks.
• vxiod---The VxVM I/O daemon provides extended I/O operations without blocking calling processes. Several vxiod daemons are usually started at boot time, and continue to run at all times.
• vxrelocd---The hot-relocation daemon monitors VxVM for events that affect redundancy, and performs hot-relocation to restore redundancy.