Are Primary Partitions Preferred?

[Daddyman]

Is it better to make all partitions on a disk primary partitions, even if they do not contain an operating system, i.e., they are data partitions? (Presuming that you don't need more than 4 partitions on a disk.)

This is the way I'm setup now - all my partitions are primary partitions - and it's based on something I read about two years ago. Of course, technology never stands still, so it may be that the original reason for doing this no longer applies. (Or possibly I misunderstood the advice I read. )

According to what I read: The starting and ending sectors of a primary partition are listed in the partition table, so these partitions are easy to find (and back up). The start and end sectors of a logical partition are stored in the previous and current logical partition. Logical partitions are then strung together in a chain, with the current logical partition pointing to the location of the next logical, etc.

This is not an issue until you have disk problems. Let's say, for example, that you have six logical partitions. Something happens on your disk to corrupt logical partition 3. The result is a corrupted logical 3 partition and an inability to find logical partitions 4, 5, and 6. They are still on the disk, but it may take forensic tools to recover them.

Is the above correct and, therefore, it is better to have primary partitions by default?

 

[ignatzatsonic]

I have not heard of that issue, but........

I don't see any reason NOT to use primary partitions unless forced to logicals. I'm not aware of any obvious advantage to having logicals for data partitions.

I'd like to hear about advantages to logicals myself, if any.

 

[TVeblen]

I do not know all that much about the inner workings of the MBR so I can't confirm or deny what you have read. But it sounds plausible. Whether or not that makes logical partitions worse than primaries is doubtful in a modern OS. It certainly makes a big difference when installing an OS, but for data I doubt it changes much at all in terms of use and maintenance.

Modern Operating Systems like W7 will create primary partitions by default. This is most likely because short of having more than 4 partitions there is no reason why not to. It's just a simpler setup.

In older legacy BIOS systems using a Master Boot Record file system the user is limited to 4 primary partitions by design. If you try and add a fifth primary partition the system will default to Dynamic Disk. To have more than 4 partitions in a MBR system you then must create the extended partition and logical drives. For most people Dynamic Disks are not recommended. We get many posts here from folk having problems after accidentally converting to Dynamic Disks.

If you have a newer system using a UEFI or hybrid BIOS then your hard drive is most likely using the GPT file system. In GPT you can have as many as 128 primary partitions, and the need for extended partitions with logical drives is no longer relevant.

So, primary is better by default, Logical is better in older systems with more than 4 partitions, primary is better in newer systems. IMHO

 

[Daddyman]

Thanks very much for everyone's info and advice.