Disk Geometry Constants

Several constants relating to basic disk geometry are defined for use throughout LVM. These are listed below.

The number of bytes in a sector on the disk.

 BYTES_PER_SECTOR              512

The maximum number of cylinders, heads, and sectors that a partition table entry can accomodate.

MAX_CYLINDERS 1024 Cylinders are numbered 0 - 1023, for a maximum of 1024 cylinders.
MAX_HEADS 256 Heads are numbered 0 - 255, for a maximum of 256 heads.
MAX_SECTORS 63 Sectors are numbered 1 - 63, for a maximum of 63 sectors per track.

The following is used for determining the synthetic geometry reported for Volumes employing drive linking.

 SYNTHETIC_SECTORS_PER_TRACK   63

The following defines the minimum number of sectors to reserve on the disk for Boot Manager.

 BOOT_MANAGER_SIZE             2048