what is GPT, and other partitioning questions (centos x64, large RAID array)
 

Hello,

Last night I assembled a new server... dual Intel quad core Xeons, 16GB RAM, Intel S5000PSL mobo (with latest BIOS), 3ware 9550SXU with a 2TB RAID5 array.

When I first booted the CentOS 5.1 install DVD, I went into disk partitioning and made a 15GB /, swap, and the rest in /home. CentOS displayed an error about the system not supporting booting from GPT. (Is there a way to get this to work?)

I went back into the RAID controller and "carved" a 15GB volume for the OS, which shows as sda, the rest shows as sdb. Upon reboot the CentOS installer displayed a message about not having a GPT scheme any longer and created dos disklabels (I think).

Are dos disklabels limited to <2TB? (Near) Future plans include expanding the array, and I'd like to avoid having several "carved" drives only to recombine them into a big single partition with LVM.

If GPT is required for larger than 2TB volumes, is it possible to make only sdb have GPT and will sda still boot the OS properly?

Any hints or info? Anything additional I can post to help you help me? I really don't want to end up in a situation where I will have to rebuild this system after it's in production. I've never dealt with volumes this large, and had assumed it would just work like normal. =(

Thanks!

I am not very sure but I believe that centOs installer uses fdisk for initial disk partitioning that why it gives you a error for GPT. fdisk tool has a limit of 2TB and you have to use a GPT partition table for bigger size.

I would suggest you to create a smaller boot and then create a LVM for the rest of the disk so that you extend it in the future.

Mether, did you ever find the solution? I am trying to get through a similar(well, the same) problem with GPT. I've never heard of GPT until a few minutes ago when I could not proceed with the install.

A quick suggestion:

When I install linux, I almost always use a live cd called Gparted (stands for Gnome Partition Editor) and it works incredibly well. I have heard (although I do not know) that fdisk has a 2 TB limit. I suggest downloading the Gparted live cd and using to partition your HDDs in ext3 (or ext4 if you really wanna be cookin with gas ;) ) And then boot CentOS after the discs are partitioned. When receiving the prompt about partitioning in CentOS, try to use existing partitions as opposed to making new ones (which is default).

I don't know if this will fix your problem but I do know that Gparted has more HDD controller support than any program I've ever seen. I always boot into failsafe mode because my SCSI controller isn't supported otherwise. Give it a try:

http://gparted.sourceforge.net/download.php

I hope I've offered a solution! :)