4 primary partitions limitation
 

My hard disk has windows 7 and kubuntu 9.10 installed.
The disk still has 1 unallocated partition.
How do I install another linux (fedora 12)?
I cannot install to the unallocated partition because hard disk can only have 4 primary partitions. The extended also counts as primary, so it can only have 3 primary partitions.
If I cannot install on this hard disk, may I install another linux (fedora 12) on an 200GB external USB disk to make the computer triple boot?

The partition layout is as follows:

Quick answer: If you have free HDD space, you can create additional LOGICAL partitions (your current linux is installed on logical partitions). Can use gparted for this or create during installation. You can re-use the swap partition you already have for the new distro. Then let GRUB know about the new distro.

You can also install on the external drive but it'll run slower due to the usb interface.

I believe the limit is 15 total partitions (4 primary, 1 of which contains the extended partitions; and 11 extended), so you could BACKUP /dev/sda6 and/or /dev/sda7, shrink either or both, move them so all your (resulting) unallocated space is at the end, and repartition that unallocated space for a new installation. Or you could add a second hard drive and use that. That's the beauty of linux, it's your choice! Either method leaves your first three existing primary partitions untouched. As an aside, you only need one swap for multiple linux installs (they can share it), but you will almost definitely want a separate /home for each one. I have heard of sharing /home partitions, but from the reading I have done it seems more trouble than it's worth, IMHO. Here's my laptop scheme:

sda1: swap 2Gb
sda2: /boot 500Mb
sda3: /data ~30Gb #shared (fstab entry in each distro to mount at /data)
sda5: / Debian Lenny ~55Gb #my primary OS, gnome DE
sda6 / Arch ~30Gb #still under construction , xfce DE
sda7: / Slackware64 13.0 ~30Gb #KDE
sda8, sda9, sda10: ~15Gb each formatted as ext3 #used for test runs

Explain this statement - which unallocated partition ?.

You do not need another primary partition for the install - Fedora will install into a logical; maybe you'll need the "expert" partitioning option during the install.
You have unallocated space at the end of the disk - use gparted to enlarge the extended partition to occupy all of that, then create a logical partition as part of the install.
No need to mess with your current setup at all.

I didn't see that, my bad. :redface:

syg00 is correct, ignore my babble. ;)

Presumably "11 extended" is a typo for "11 logical". According to this undated TLDP page the number of logical partitions is limited under Linux to 15 on a SCSI disk and 64 on an IDE disk but according to this April 09 thread the limit is 255.

Running GParted in kubuntu indicates that the disk has a 186GB unallocated "partition" after /dev/sda7. However, selecting that unallocated space and clicking the "New" button results in a "4 primary partitions limit" error.
Selecting the /dev/sda4 extended partition and clicking the "Partition" menu result in a popup menu which has the "New" menu being active, the other menus such as "Resize/Move" are unactive, so I cannot use GParted to enlarge the extended partition.
Please help.
Thanks.

Can you post a screenshot of gparted showing the partition layout?

Try it from a liveCD.

I assume you mean running it in the installed copy of kubuntu. That is the problem. You need to boot a Linux liveCD and run GParted from the liveCD.

I assume you have one or two of those liveCDs, the one you earlier installed kubuntu from and the one you want to install another Linux from.

Right. You can't create the new partition that way.

I assume from the fact that you want to enlarge it that the unpartitioned space is outside the extended partition. I think the reason it won't let you enlarge the extended partition is that Linux has mounted a logical partition inside that extended partition.

BTW, depending on the specific liveCD you boot from, that might also mount swap space or file partitions in your extended partition, so you may need to unmount those after booting the liveCD before GParted can change the extended partition.

Following your advice, I use gparted from sysrescuecd to maximize the size of the extended (sda4) primary partition which have room to add logical drives for other distributions.
The fedora 12 installation program keep the existing partitions and suggest these new partitions:
I think they are ok, aren't they?

I think LVM is needlessly complex for ordinary users and I think a separate /boot partition is unnecessary. Assuming the Fedora installer allows it, I think a single logical partition for / should be simplest.

But hopefully the fedora 12 installer in suggesting a more complicated partitioning would also follow through and help you use it. So doing it their way should be OK.

Should I install boot loader from Fedora 12?
My computer had a boot loader from kubuntu 9.10.

I always give one partition to each Linux, including every member of the Red Hat family that try to sell me the LVM. Just partition the disk first, select a partition and tell the installer to get on with it. A user only needs a separate /boot if he/she has been persuaded by the Red Hat installer to have a LVM because boot loaders can't read a LVM. People running servers have their own reasons to put a Linux over several partitions.

The maximum number of partitions Linux can create is 130, using sfdisk. 4 primaries or 3 primaries with an extended partition. AFAIK there is no limit on the number of logical partitions in an extended partition. This thread show a Xp bootable in any one of them. Linux's partitioning tools are not all coherent but most, like fdisk and cfdisk, will list up to only 63 partitions. Gparted is the only program willing to offer beyond the 130 partitions limit but a few lines of script with sfdisk can generate 130 partitions in seconds.

Linux's Grub and Win7's bootmgr can multi-boot possibly any number of OSes as I have them done over 150 systems each. Any Grub, either Grub1 or Grub2, from any Linux in any partition can be used take over the MBR to multiboot all systems in the box.

The space after the 4 primaries (or 3 primaries + an extended) is dead unless it follows an extended partition like the OP. The cfdisk program can be run to increase the number of logical partitions.

The OP partition table is
The blue bits tell us the extended partition terminates at 53510 cylinders but the red bit tells us there are 77825 cylinders in total. Therefore extended partition can be pushed downward and the correct tool to do this is cfdisk using command
. The 3 primaries sda1, sda2 & sda3 are all before the extended partition sda4 and will not interfere with the additional logical partitions creation. A set of logical partitions must be created as a continuously and consecutively in a hard disk because the (i)th logical partition carries the address of (i+1)th logical partition.

Please confirm that your suggestions are:
- a single logical partition for / should be simplest. i.e. no need for LVM and /boot partition
- no need for Fedora boot loader, the existing linux boot loader is ok