[linux] booting 2+Tb disk with GPT in el6
lombaard at u.washington.edu
Wed Jun 15 22:43:32 PDT 2011
I recently found out the hard way that MBR & > 2Tb does not work. I found this site useful:
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):
> 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
> * 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
> * LDAP
> new nss-pam-ldapd means config files are now /etc/pam_ldap.conf and
> * el6 still uses grub-0.97 (Ubuntu is using the much different grub2)
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