Logical volume programming
The Logical Volume Manager (LVM) consists of the library of LVM subroutines and the logical volume device driver, described as follows:
- Library of LVM subroutines. These subroutines define volume groups and maintain the logical and physical volumes of volume groups.
- Logical volume device driver. The logical volume device driver is a pseudo-device driver that processes all logical I/O. It exists as a layer between the file system and the disk device drivers. The logical volume device driver converts a logical address to a physical address, handles mirroring and bad-block relocation, and then sends the I/O request to the specific disk device driver. Interfaces to the logical volume device driver are provided by the open, close, read, write, and ioctl subroutines.
For a description of the readx and writex extension parameters and those ioctl operations specific to the logical volume device driver, see the Kernel Extensions and Device Support Programming Concepts.
For more information about logical volumes, see the Operating system and device management.