[CentOS] Large disk support

Joshua Baker-LePain jlb17 at duke.edu
Tue Nov 28 21:03:19 UTC 2006

On Tue, 28 Nov 2006 at 12:56pm, Kevan Benson wrote

> I have a 3.5 TB RAID 5 Array through a 3ware 9590SE 8 port card, and am
> running into what seems like quite a lot of problems trying to get the system
> installed correctly.  The system is a running dual Opterons with 2 GB of RAM,
> and I'm attempting to install through the x86_64 ServerCD.
> First, grub refuses to install on the disk, as it's too large.  I can get
> around this though by booting Fedora Core 6 in rescue mode and running grub,
> as it can deal with the disk size correctly.  This might only be working when
> I attempt installs that don't utilize as much of the array as possible though
> (100 MB /boot, 2GB swap, 10Gb /, the rest left unallocated).
> Secondly, there seems to be a problem using msdos disk labels with large
> partitions, and I can't seem to find any solutions to this in the manuals or
> on the net.  GPT labels are offered as a solution to this but only for
> Itanium systems.
> Am I missing some obvious solution to this?  Are there some best practices for
> dealing with large disks anyone can share that may save me problems now or
> later?  I'm open to suggestions, as all I've encountered so far are problems.

1) You cannot use a msdos disk label on a disk >2TiB.  You must use GPT.

2) No current boot loader understands GPT disk labels.

3) Therefore, you cannot boot from a disk >2TiB.

Possible solutions are:

1) Install a 2nd disk/array for the OS, and use the big array for data.

2) Turn on the 3ware's auto-carving feature, which will divide the single
    RAID volume into multiple disks, none larger than 2TiB.

Joshua Baker-LePain
Department of Biomedical Engineering
Duke University

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