What is a physical extent?

What is a physical extent?

Each physical volume is divided chunks of data, known as physical extents, these extents have the same size as the logical extents for the volume group. Prev.

What is a logical extent?

Each logical volume is split into chunks of data, known as logical extents. The extent size is the same for all logical volumes in the volume group.

What is LVM logical extent?

The extents on a physical volume are called physical extents, while the extents of a logical volume are called logical extents. Because of this relationship, the extent size represents the smallest amount of space that can be allocated by LVM. Extents are behind much of the flexibility and power of LVM.

Why are there more than one logical extent?

Because the second logical volume is mirrored, each logical extent is mapped to more than one physical extent. In this case, there are two physical extents containing the data, each on both the second and third disks within the volume group.

How are physical extents assigned to logical volumes?

In this case, there are two physical extents containing the data, each on both the second and third disks within the volume group. By default, LVM assigns physical extents to logical volumes by selecting available physical extents from disks in the order in which they appear in the LVM configuration files, /etc/lvmtab and /etc/lvmtab_p.

What is the physical and logical structure of Oracle?

Physical database structure. The physical database structure comprises of datafiles, redo log files and control files. Datafiles. Datafiles contain database’s data. The data of logical data structures such as tables and indexes is stored in datafiles of the database. One or more datafiles form a logical unit of database storage called a tablespace.

When do physical extents need to be contiguous?

If a logical volume is to be used for root, boot, primary swap, or dump, the physical extents must be contiguous, which means that the physical extents must be allocated in increasing order with no gaps on a single physical volume.