Hello,

I have a HP Proliant ML350 G5, with a RAID P400 smart array (6 x 750 GB disk). RHEL 5.1 is certified to run on this machine.

After booting the server on the first CentOS 5.1 installation CD, the installation process seems to work perfectly (RAID array supported with cciss driver). But anaconda stops a the moment of partitionning with the error :
"your boot partition is on a disk using the GPT partitioning scheme, but this machine cannot boot using GPT". It seems impossible to go further with CentOS 5.1.

As it seems not possible to choose something else than GPT, I have try with CentOS 4.6 with no GPT support (using small partitions of 1 TB). This time, everthing went fine during the install process (the RAID array seems perfectly supported), BUT ... the installed system does not boot from hard disk ! However, booting from the CD in rescue mode after this installation shows that everything is fine.

Does anyone know how to install CentOS/RHEL on the Proliant ML350 G5 ?

(by the way, I have not been able to boot from an USB drive either, even whith a simple dd of the diskboot.img)

Thanks by advance,


Pierre Reinbold

You can't boot from a gpt labeled disk ...
Why not using a standard dos labeled disk , create a small /boot partition and use lvm for the remaining space ? That's always what i do ...

Hi Fabian, thank you for our answer !

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That's also what I do usually, and I have try that in many ways this time. The machine has a SATA interface along with a standard Fast IDE interface; I have try both (with two different disks). The installation went well with /boot on these supplementary disks, but the server refuses to boot on them. It seems impossible to activate these devices in the BIOS boot sequence. I have even try to install the /boot on a USB key, and it was my most successfull attempt : the system is installed, the key is in the boot sequence, grub load its stage one, but freeze while loading stage two ! I have double-check, in rescue mode, the root drive identification in the grub.conf, and all seems right. By the way, this sever also fail to boot on a USB stick prepared with "dd if=images/bootdisk.img" (i.e. the RedHat standard way).

I am really confused right now...

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It may be a silly question, but why so ? Have you got a pointer to some clear documentation about GPT ?

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Ok, after some googling I have found the answer to that question.

But, has the proliant is initialized by a BIOS, why is CentOS 5.1 using GPT as partition scheme ? And is there a possibility to deactivate this scheme in order to boot from the RAID ?

GPT is required for disks/arrays that are bigger than 2TB. The old DOS partition table format is limited to <2TB disks/arrays.
Booting from a disk with a GPT label requires EFI BIOS and an EFI-compatible boot loader. The version of GRUB in CentOS 5 doesn't support GPT or EFI.

Is it possible in the P400 to say: "Lets have two arrays on these disks, first a small RAID1, and second a big RAID5"?

If P400 allows such, then first array could have the DOS label, and the second a DPT?

@markkuk : Ok, thanks for these informations.

So, basically, my problem remains the same :
- the array *must* be partitionned with GPT as I want to keep the 3.7TB in RAID 5
- CentOS 5 is not able to boot from GPT and anyway, the Proliant uses an old PC BIOS instead of an EFI, so the system *must* boot from another device
- *but* the BIOS configuration does not seem to allow the use of another boot device

I will go again through the BIOS parameters to seen if I have missed something...

@jlehtone : Yes, in fact, such a setup *is* possible on the P400. I wanted to avoid that, but it may be the only acceptable solution if it is really not allowed to boot from another disk (and I find that hard to believe from HP). Thank you very much for this suggestion anyway !

We had hit the same issue but nailed it today. We created one raid 5 array with all the drives (3.5 T) and then created two logical drives on it. (1 GB and 3.4T) using HP ACU. Installed boot to 1 GB drive and rest to 3.4TB. Hope this helps

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1GB drive is MBR formatted?

This is what i did.

If you have this problem from within the Centos Partition GUI press Ctrl+Alt+F2 to get to console mode and the 'urandom' for a couple of minutes. Note that you don't need to do the whole drive.

#dd if=/dev-urandom of=/dev/<hdd device node>

Reboot the machine and then you should be able to create the partitioning you require