# FDISK? Extended Partitions?



## TheReaper (Jan 23, 2005)

I know the basics of FDISK, and that to install WinXP you have to have a primary partition and stuff. I know that Windows 95 requires an Extended DOS Partition. Could someone explain what the other partitions are and what they're used for? I'm fixing a computer illiterates box running W95, and I'm begining to sound like one too. Nooooooo


----------



## DaveBurnett (Nov 11, 2002)

A disk can only have up to 4 Primary Partitions defined.
Now 4 is not enough, SO.... one of these primary partitions can be a special one called an Extended Partition which is just a 'shell'. This Shell can then contain up to 36 Logical partitions.
Windows 95 has no special requirements for partitions. All DOS based operating systems can only BOOT from a normal primary partition and that partition MUST start within the first 1024 addressable cylinders (IE the first 8Gb of the allocated space).


----------



## Bob Cerelli (Nov 3, 2002)

"Could someone explain what the other partitions are and what they're used for?"

What other partitions are you seeing?


----------



## Topazz (Sep 16, 2000)

This site will tell you everything you need to know about FDISK but if it doesn't have the answer to what you need to know you will have to provide more information.


----------



## Elvandil (Aug 1, 2003)

Here is more information than you will need about those other partitions (and some you won't see):

http://www.computerhope.com/jargon/p/partitio.htm

Note that the historical limit of 4 primary partitions can be overcome by many newer partitioning applications (though I haven't seen more than 9).


----------



## Bob Cerelli (Nov 3, 2002)

What partitions are on the computer right now?

As previously mentioned, you don't need an extended DOS partition for Win95. It does however have a 2 gig partition size limit. For that reason, with drives over 2 gigs, there might be an extended DOS partition with logical drives of 2 gigs each. One reason why Win98 was a bit better.

Also, Win95 would need a primary partition and it needs to be active if you are going to boot from it.

I'm not really sure why the information about having 4 primary partitions would be necessary for such a simple request. Although it may be technically accurate, it seems to have nothing to do with what you want to accomplish.

===========

Information on how to use FDISK can be found at:
http://www.onecomputerguy.com/install/fdisk.htm

Topics covered are:
Overview and Getting Started
Partitioning a New Drive - Single Large Partition
Partitioning a New Drive - Multiple Partitions
Deleting a Single Partition
Deleting Multiple Partitions
Deleting a NTFS Partition
Fixing the Master Boot Record


----------



## TheReaper (Jan 23, 2005)

Thanks people.

The hard drive is just over 2.5 gigs so it's clear now why there's a 500M extended partition.

Thx,
Reaper


----------



## DaveBurnett (Nov 11, 2002)

> Note that the historical limit of 4 primary partitions can be overcome by many newer partitioning applications (though I haven't seen more than 9).


Pray tell. I know of ways of getting at extra areas of the disk though software, but there are only 4 entries in the partition table, so it would have to be an application running in the background to access more than 4 at once.


----------



## Bob Cerelli (Nov 3, 2002)

I'm still not sure where the whole thing about having 4 primary partitions relates to what the person was asking. Other than a technical possibility, how does it relate to helping them simply reinstall Win95.


----------



## DaveBurnett (Nov 11, 2002)

I answered the question that I thought was asked, and that was what the meanings of what the different types of partitions were. Although he mentioned Win95 in the original post, I read his question to be a general one and therfore I gave an explanation of the principles rather than a specific case.
It wasn't until his last Post that the actual size of the disk was mentioned, thus perhaps clarifying the reason for the original question.


----------



## Bob Cerelli (Nov 3, 2002)

"A disk can only have up to 4 Primary Partitions defined. Now 4 is not enough"
Why isn't 4 primary partitions enough?

"one of these primary partitions can be a special one called an Extended Partition"
Is a Primary an Extended Partition? 

When I run FDISK you have the option for either a Primary or an Extended partition. With an Extended Partition, you can then create logical Drives. But I haven't seen the ability to create a special Primary Partition that is an Extended partition. What are the details for doing that.

"This Shell can then contain up to 36 Logical partitions" - Are these the same as logical drives? If so, how do you name all 36 of them since typically you use the letters of the alphabet for naming drives (with typically A:, B:, and C: already being taken). Again, any specifics would be helpful.


----------



## DaveBurnett (Nov 11, 2002)

> Why isn't 4 primary partitions enough?


4 partitions(total) is not enough, hence leading to the reason for Extended and Logical.



> Is a Primary an Extended Partition?


No, but but an Extended partition IS always primary. Have a look at what Partition Magic says about it.

The correct term for an extended partition IS Extended Primary. The Primary meaning, in the case of partitions, defined in the partition table.

Logical partitions are Secondary partitions since they are NOT defined in the partition table and have to be, in fact, defined by the operating system.

A lot of confusion arises because, over the years, the terms have been shortened or dropped and what is left has lost its true meaning.


----------



## Bob Cerelli (Nov 3, 2002)

I thought he was talking about FDISK and not how Partition Magic labels partitions.


----------



## DaveBurnett (Nov 11, 2002)

I only mentioned Partition magic as an example of the correct terminology. Anyway to get back to your earlier question.


> "This Shell can then contain up to 36 Logical partitions" - Are these the same as logical drives? If so, how do you name all 36 of them since typically you use the letters of the alphabet for naming drives (with typically A:, B:, and C: already being taken). Again, any specifics would be helpful.


Logical partitions and logical drives are not really the same thing since ALL partitions are logical drives as opposed to physical drives - again the common use of the term logical drive has become clouded. If you have a computer with just 1 disk with two primary partitions, how do YOU refer to the drives. I contend that they are (In DOS) logical drive C and D and are both on the first physical drive.
Anyway, back to the logical partitions.
Should you choose to you could define a disk as having just an Extended Primary partition and have 36 logical partitions within it. You could be booting Dos from a floppy, or you could install XP into one of them. 
We are talking here about theoretical possibilities allowed by the definitions. Nobody in their right mind would actually do it --- or would they


----------



## Bob Cerelli (Nov 3, 2002)

I'm still not clear with all the terms.

Primary Partitions
Extended Partitions
Extended Primary partitions
Extended Other Types of partitions
Logical Drives
Logical Partitions

Good thing to know not a lot of people in their right mind would do a lot of all that.

Generally, for something as simple as Win95, I would just keep it simple.


----------



## DaveBurnett (Nov 11, 2002)

There are only three things:
Primary Partition of which there is one special type Called an Extended Primary Partition.
Logical Partitions which have to live inside an Extended Primary Partition.
ANY partitiion, once it is given a drive letter becomes a Logical Drive.

Why do people climb Mountains???


----------

