Linux primary partition, extended partition, logical partition connection and Difference

I remember when I first installed the Linux operating system, know some Linux disk partition knowledge, but with the passage of time, a while, the basic completely forget, vaguely remember as if once knew there is such a thing. Human memory is like this, so once the choice of an industry, it is best not to easily change, because a lot of knowledge needs to be repeated to really grasp, and an industry needs a lot of real knowledge, some people call this is the process of accumulation. In any case, no matter what industry is not to boil a few overnight to take care of. And your accumulation will become to want to turn the barrier of others, the more you accumulate, the higher the barrier. So once you choose, you have to go on, I believe in the near future you will see a different dawn, because there are many people halfway down the road. I firmly believe that.

in the process of installing CentOS5.3, you will encounter a disk partition interface, the drop-down menu has 4 options, you do not choose the default, open the drop-down menu, select the last item (translated into Chinese means: Create a custom split mode). Then select the confirmation in the lower right corner and set up/////////and swap in the next dialogue screen, after completion. Confirm the split area after setting.



in order to emphasize the emphasis, the important content of the picture, write again.

/root directory ext3 hda1

/home User directory ext3 hda2

Swap swap partition swap Hda3

explanation of the hda1:

hd:ide hard drive. If it is a SCSI hard disk, then SD, this can only remember, there is no better way.

A:: First hard drive. If it is a second hard disk, then B, and so on C,d ...

1: Primary partition. Where 1,2,3,4 is the primary partition, starting from the 5th logical partition, Max to

the relationship between disk capacity and primary partition, extended partition, logical partition:

Capacity of the hard disk = capacity of primary partition + capacity of extended partition

capacity of the extended partition = The sum of the capacity of each logical partition

A physical hard disk can only have: one to four primary partitions (but only one of which is the active primary partition), or one to three primary partitions, and one extended partition. correspond to HDA1,HDA2,HDA3,HDA4 respectively.

Linux stipulates that each hard disk device can have up to 4 primary partitions (including the extended partition), any one of the extended partition will occupy a primary partition number, that is, on one hard disk, the primary partition and the extended partition total is 4.

The confusion I had was: I didn't know that the extended partition would occupy the primary partition (up to 4) a partition number.

My summary: A hard disk can only set the primary partition, then the primary partition can be set up 4 area code. It can also be set to the primary partition + logical partition, which is also a maximum of 4 partition numbers, but becomes 4 = 3 + 1. Where 4 is the primary partition and the extended partition add up to 4, 3 is the primary partition, can be less than or equal to 3, and 1 is the extended partition number, which occupies a primary partition number. From 5 to 16, all are logical partitions. If there is only one 5, the extended partition is no longer partitioned, and the extended partition is the logical partition (the total number of disks in the extended partition equals the total number of disks in a logical partition). It is common for extended partitions to be partitioned into several logical partitions, identified by numbers such as 5,6,7,8.

again to understand the above partition:

/root directory ext3 hda1 Active primary partition, start OS

/ Home User directory ext3 hda2 primary partition

Swap swap partition swap Hda3 primary partition

This may imply that there is an extended partition, which should be hda4. Because you can also set Hda5,hda6 in the back,......

It is also possible that there are only 3 primary partitions (up to 4) that are already full of disk capacity.

Linux primary partition, extended partition, logical partition connection and Difference