Why extended partition

MBR hard disk supports up to 4 primary partitions. If users need more partitions, they need an extended partition record EBR which is stored on extended partition. Therefore, users can divide the extended partition into multiple logical drives.

Since the master boot record can contain up to 4 entries of primary partition, users can turn to the FDISK partition command to create an extended partition with multiple logical drives. And the information of all logical partitions is stored on the extended partition, while the primary and extended partition information is stored on the MBR of hard disk. In other words, the master boot record only contains the information of primary partition and extended partition regardless of how many partitions are created on the hard disk.

Otherwise, you will not be able to boot your computer. There is no difference between the two kinds of partitions in the ability to store data. There is no speed difference between them. By using an extended partition you can now have up to 15 partitions per disk. The partition structure of a hard disk might look like that in Figure The disk is divided into three primary partitions, the second of which is divided into two logical partitions.

The step by step below will demonstrate how to create extended partition using command prompt and Windows Disk Management snap-in. A recovery partition is a partition on the disk that helps to restore the factory settings of the OS operating system if there is some kind of system failure.

This partition has no drive letter, and you can use only Help in Disk Management. An active partition is based on primary partition. Any one of the 4 primary partitions can be set as active partition. Select the partition or logical drive you want to delete and choose the command to delete the partition or logical drive from the context menu.

You are prompted for verification. Click Yes to delete or No to cancel. The partition or logical drive is removed immediately if you click Yes. A primary partition is one that can be used as the system partition. If the disk does not contain a system partition, you can configure the entire disk as a single, extended partition. There can be only one extended partition on a hard disk.

Within the extended partition, you can create any number of logical drives. As a practical matter, the number of available drive letters is the limiting factor in the number of logical drives that you can define. When you have an extended partition on the hard disk, the entry for that partition in the Partition Table at the end of the Master Boot Record points to the first disk sector in the extended partition.

The first sector of each logical drive in an extended partition also has a Partition Table, which is the last 66 bytes of the sector. The last two bytes of the sector are the end-of-sector marker.