Hi,

I am new to the installation of Linux, and wish to install 3 different distro's on the same hard disk.

I have installed Centos 7 successfully as follows :

The /boot is /dev/sda2

/dev/sda1 is listed as unknown so i assume it is the Master Boot Record with Grub installed. I do obtain the option to boot to the various kernels after updating the OS.

/dev/sda3 is a Linux LVM with the various partitions i required.

When i installed the CentOS 7 the installer stated an error about the bootable partition - which was effectively /boot, so i moved this to /dev/sda2.

What i am not sure about is that if i want to install 2 other Linux OS's will i run out of /dev/sdaX assignments ?.

I read somewhere that there are 4 maximum that can be used a /boot (SDA1, SDA2, SDA3, SDA4), so does this mean i can only install one other OS ?.

Any guidance gratefully received. Thanks.

Regards,

Richard.

No, more likely a Windows partition - NTFS."an error" tells us nothing - post exact message(s) in future. Do you mean you moved the boot flag to /dev/sda2?.
Linux is (much) more flexible than Windows, and can use logical partitions - even for /boot. Some (Linux) installers won't do this easily (RHEL and CentOS come to mind), you have to use the "Advanced" partitioning option at install.

From a terminal in Centos, run this command and post all the output

Hisyg00,

I did use advanced - so i thought so only have one distro installed at the moment.

Output from command you provided is :
So is the 500MB 1 partition grub ?.

I do not recall ever installing Windows on this disk - was a clean Linux installation - CentOS 5 originally.

As such - do i have to reinstall or can i move the partitions around etc ?.

I was planning to install Fedora 21 on the other partitions, or Fedora 21 as second Linux build, and possibly CentOS 6 on the third.

Thanks and regards,

Shadders.

Ugh - edit that and change the [quote] tags to [code]. That way the layout is maintained - use [code] for all output.

Create an extended partition using all that free space, then you can allocate multiple logicals within it as needed - the extended is merely a container. It gets you around the MS-DOS limit of 4 primary partitions. See wikipedia for an explanation.
No need to move anything around. Looks like no filesystem in /dev/sda1 - basically unused.
The boot flag is ignored by grub, so just leave it there.

So just install what you want - BTW F22 is now out; install that rather than F21.

Hi Syg00,

Thanks for the assistance - much appreciated. I updated the text to CODE.

Regards,

Shadders

What distro's are you trying to install?
Some distro's such as debian can be installed without installing grub to the mbr, which would be a good thing because whatever grub you end up with would have to be able to access n lvm partition such as ubuntu's, or I believe you would have to create a new initrd image with support for lvm.

HI Eddy1,

I was installing rpm based distro's - Fedora, Centos, possibly Scientific Linux. I purchase Linux Format regularly so will use their DVD's with distros to try. I essentially want two builds at least to experiment on, in different ways - so the separate installs are required. Thanks.

Regards,

Shadders.

I think that fedora & centos both use lvm so I would believe that it is safe for either of them to control grub.

Hi Eddy1,

Yes - i have not loaded any programs i wish to use just yet so if it all goes wrong, i am ok, and it does mean i can experiment a bit too. Thanks.

Regards,

Shadders.

Yes you can experiment, but if it all goes wrong after installingthe other distro's don't remove them just remember where ubuntu's grub was installed & boot up the ubuntu dvd/usb, in rescue mode & reinstall grub. You'll find ubuntu easier to manage grub & it will find & add the other OS's to it's grub.

I had XP, XP 64, and Windows 7 installed on my workstation for testing. I installed three hard drives. I installed the oldest first. I created a separate boot sector and separate C: drives as primary. This way the three OS could not write or see the other OS partitions and corrupt them. I kept separate hard drives for space for applications for each. So I can't see why Linux can't do it. Use Grub it is common to move flavors.

if you install cent then THERE IS NO!! REASON!!! to install Scientific linux

they ARE REALLY THE EXACT SAME OS !!!!

just a few different icons and background images

also PUT !!! fedora's grub2 on the MBR and not centos's legacy grub0.9

Hi All,

Thanks for the advice. I will use Fedora grub2 - but i have already installed CentOS 7 - so will installing fedora as the second OS overwrite the existing Grub with the new version ?.

I know Scientific Linux is the same as CentOS ., but i thought it was more of a beta than CentOS ?, offered some changes that were not in the official CentOS distribution.

I could install a debian based OS - as i have no experience of that.

Thanks and regards,

Shadders.

If you accept the default for the bootloader installation with Fedora, it should ovewrite the Grub installation from CentOS although I believe CentOS beginning with 7.0 now uses Grub2. You don't indicate which release you have, the 6.5 version I tried still used Grub Legacy.

Nope
cent and sl use the EXACT SAME code base RHEL

sl is created by the good people at FermiLab - usa and at CERN - Geneva

now Cent adds a few DESKTOP related things to the RHEL code

SL adds a few scientific things

but for all that matters they ARE THE SAME
Just minor differences
one of witch is SL has SECURITY backports to older versions like 6.5 and 6.4

cent DOSE NOT !!!!