W95 Ext'd (LBA) Partition

Linux Tutorials - Herong's Tutorial Examples

∟W95 Ext'd (LBA) Partition

This section provides a quick introduction on W95 Ext'd LBA (Windows 95 Extended Logical Block Addressing) Partition, which is actually a container to hold sub-partitions.

If you are using a hard disk create from a Windows computer, you may see a special partition with the "W95 Ext'd (LBA)" type. W95 Ext'd (LBA) stands for Windows 95 Extended Logical Block Addressing.

"W95 Ext'd LBA" is not a file system partition. It is actually a container to hold sub-partitions. On Windows systems, a hard disk can only be divided up to 4 partitions. "W95 Ext'd LBA" technology allows you create more sub-partitions from those 4 primary partitions.

If you see a hard disk that has more than 4 partitions, or you see a partition index higher than 4, you know that "W95 Ext'd LBA" is used on the hard disk.

For example, I have the following partitions on my CentOS computer:

herong$ sudo fdisk -l /dev/sda

Disk /dev/sda: 900.0 GiB
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disklabel type: dos

Device     Boot      Start        End    Sectors   Size Id Type
/dev/sda1  *          2048  167776255  167774208    80G  7 HPFS/NTFS/exFAT
/dev/sda2        167776256 1953523711 1785747456 851.5G  f W95 Ext'd (LBA)
/dev/sda5        167778304 1748721663 1580943360 753.9G  7 HPFS/NTFS/exFAT
/dev/sda6       1748723712 1750820863    2097152     1G 83 Linux
/dev/sda7       1750822912 1953523711  202700800  96.7G 8e Linux LVM

The output tells me that:

The hard disk has only 2 primary partitions /dev/sda1 and /dev/sda2.
/dev/sda1 has 80 GB in Windows NTFS format with the boot sector to serve my Windows system
/dev/sda2 has 850 GB in "W95 Ext'd LBA" format and contains 3 sub-partitions: /dev/sda5, /dev/sda6 and /dev/sda7.
/dev/sda5 is sub-partition with 753 GB in Windows NTFS format.
/dev/sda6 is sub-partition with 1 GB in Linux format to hold Linux /root files.
/dev/sda7 is sub-partition with 96 GB in Linux LVM format to server my Linux system.