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maximum disk partition???

 
Jack Fan
Regular Advisor

maximum disk partition???

Hi All,
I have create over 9 disk partition c0d0p1~c0d0p9....but red hat linux default partition amount is 7 per one disk.

How can I use fdisk and create partition exceed 7?

Thanks,

Jack Fan
7 REPLIES 7
Jarle Bjorgeengen
Trusted Contributor

Re: maximum disk partition???

Hi Jack,

can you please explain a bit further ?

You say you have created 9 partitions, and you wonder how to create more than 7 ????

It is no problem to create as many partitions as you want.

There is a limit of 4 primary partitions on one disk though. All you need to do is to make one of the primary partitions a extended partition, then you can make lots of logical partitions inside the extended partition.

Rgds Jarle

twang
Honored Contributor

Re: maximum disk partition???

According to standard fdisk-style partitioning, you can only have a maximum of eight partitions (a to h) per drive.
Bill Douglass
Esteemed Contributor

Re: maximum disk partition???

What type of machine is this, and what distribution/version of Linux are you using?

From the fdisk man page (this is RH 7.3):

IDE disks can have up to 63 partitions, SCSI disks up to 15.


If you're using Sun disk labels, you can only have 8 partitions, with #2 being the whole disk.

Using an msdos disk label, you can get the maximun # of partitions for your device type using logical parts within an extended partition.

Jack Fan
Regular Advisor

Re: maximum disk partition???

All,

Here is further information,

1. I have install a MyLex disk array card, also create a logical disk array.

2. I have create two partition one for root /dev/rd/c0d0p0 and one for swap /dev/rd/c0d0p1. It is available.

3. After booting successful, then I attempt to create 6 disk partition on disk /dev/rd/c0d0, and device name is /dev/rd/c0d0p3, c0d0p4(extend partition), c0d0p5, c0d0p6, c0d0p7, c0d0p8, c0d0p9. then 'w' write to disk and exit, and reboot server.

4. The linux have to do partition check while os booting through c0d0p1 to c0d0p7, thus I can create filesystem for these partiton and mount it. But c0d0p8 and c0d0p9 doesn't work.

5. I have find those device file through c0d0p1 to c0d0p7 on /dev/rd/ directory. My question is where is c0d0p8 and c0d0p9, how do I create those device file?

Please advise....Thanks,

Jack Fan
benoit Bruckert
Honored Contributor

Re: maximum disk partition???

Hi,
this is not a solution but just a remark. If you play with many partitions, it would be easier in this case to use lvm (you create just one physical partition), and then create all the logical partitions you want over it .
I'm playing with it and it works like a charm.
hth
Benoit
Une application mal pansée aboutit à une usine à gaze (GHG)
Jerome Henry
Honored Contributor

Re: maximum disk partition???

Ok,
your partitions are here !
On your HD, you can create up to 15 partitions per IDE disk, 63 partitions in a whole (supposing you use several HDs).
The partitions positions is written in a place called Master Boot Record (MBR). It can contain 4 addresses, so 4 partitions.
For that reason, these partitions are said "primary partitions".
To make more than 4 paritions, one is used as a container for other paritions. This one will be called extended parition, and will contain logical partitions, which addresses will be written in the first sectors of the extended partition, and not in the MBR. You can set up up to 12 partitions of this kind.
Now let see where your partitions are :
You have a primary partition 1
A primary partition 2
At this stade, you can still create 2 primary partitions, or a primary and one extended. What you do is that you create an extended. So you do not have primary 3, directly primary 4, which is not a partition by itself, but a container for your logical partitions.
And then you create logical 1 (n??5), 2 (N??6), 3 (N??7), 4 (N??8) and 5 (N??9).
You can still create 3 others if you have space.
Now you reboot, and you system sees 2 primary partitions, OK, and 5 logicla partitions (7in a whole). It doesn't see primary 3 which doesn't exist and 4 which is a container.
Nothing is lost, your system just call them 1,2,3,4,5,6 and 7...
Got it ?
J
You can lean only on what resists you...
I_M
Honored Contributor

Re: maximum disk partition???

Hi

You may read /usr/src/linux-2.4/Documentation/devices.txt to find out how many partitions you can create on scsi or ide disk.