[linux] booting 2+Tb disk with GPT in el6

[S Lombaard]

I recently found out the hard way that MBR & > 2Tb does not work. I found this site useful:
http://www.cyberciti.biz/tips/fdisk-unable-to-create-partition-greater-2tb.html

Regards,
Stefan



On Mon, 13 Jun 2011, Joshua Daniel Franklin (UW Seattle) wrote:


> Possibly interesting info, it's now fairly easy to boot off of 2Tb+ drives in 

> Red Hat EL6, though getting it to work is not obvious. For example, if you do 

> a default Red Hat EL6 install on a 64-bit Dell PowerEdge server you will get 

> an MSDOS disk label.

>

> The secret is that the disk label must be GPT (GUID Partition Table) which is 

> not the default for BIOS-based x86 machines (Macs and Itanium use EFI/GPT). 

> Once a GPT disk label exists the installer will use it. I'm not clear on 

> precisely what's going on with grub, the MBR, etc but it works. I did find a 

> utility "gdisk" aka "GPT fdisk" http://www.rodsbooks.com/gdisk/ which has 

> lots of details about GPT.

>

> Here are two ways to install with GPT as disk label on Red Hat EL6:

>

> 1. In the graphical installer, before partitioning switch to a shell 

> (Ctrl-Alt-F2) and run "parted /dev/sda" and "mklabel gpt". You can now 

> proceed as normal in the install, including automated or customized 

> partitioning, LVM, etc.

>

> 2. Using kickstart, make sure you don't use "zerombr" or "clearpart --all" 

> which recreate an MSDOS disk label ("clearpart --linux" is fine) and add 

> something like this (the "dd" is only really necessary if you need to destroy 

> an old disk label first):

>

> %pre

> dd if=/dev/urandom of=/dev/sda bs=512 count=64

> parted -s /dev/sda mklabel gpt

>

>

> Unfortunately I did not have any luck getting GPT booting to work with Ubuntu 

> 10.04, but I didn't try very hard. The installer seemed to always create a 

> MSDOS label, and  "parted" is not available on the Ubuntu 10.04 installer's 

> shell, only "fdisk". Surely that will change soon with single 3Tb disks 

> already on newegg, though perhaps EFI will become mainstream first. 2Tb disk 

> limits are just one of many things like 32-bit Windows that I thought would 

> be long gone by 2011.

>

>

> Some other random el6 notes:

>

> * ISOs for 6.1 available from https://www.washington.edu/uware/rhel/

>

> * if you want to boot the el6 installer using USB, you have to make your own 

> diskboot.img using a new enough syslinux (like another el6 machine). Details 

> at the bottom of http://trac.biostr.washington.edu/trac/wiki/KickStart

>

> * a bunch of the package group names have changed since el5 so you're best 

> using "yum grouplist", system-config-kickstart, or looking at the comps which 

> are now on the installer at places like 

> repodata/00fa55cde0056779ce3cb404c5097825124da4bae5823734c9978798d64428bb-comps-rhel6-Server.xml.gz

>

> * rpm format has changed slightly so if you want to extract files you'll need 

> to use el6 (or newish Fedora)

>

> * NetworkManager

> If you install NetworkManager, you may want to change this new line to "no" 

> in /etc/sysconfig/network-scripts/ifcfg-eth0

> NM_CONTROLLED="yes"

>

> * LDAP

> new nss-pam-ldapd means config files are now /etc/pam_ldap.conf and 

> /etc/nslcd.conf

>

> * el6 still uses grub-0.97 (Ubuntu is using the much different grub2)

>