[CentOS] bugs with large partitions

Mon Apr 25 15:22:58 UTC 2005
Joshua Baker-LePain <jlb17 at duke.edu>

On Mon, 25 Apr 2005 at 4:12pm, John Moylan wrote

> I installed centos4 on a raid system with 7 400GB Hitachi SATA disks in
> RAID 5 on the 3Ware card. I set up a 2.2TB EXT3 Partition /opt.
> 
*snip*
> Using /dev/sda
> (parted) print
> Disk geometry for /dev/sda: 0.000-2288754.000 megabytes
> Disk label type: msdos
> Minor    Start       End     Type      Filesystem  Flags
> 1          0.031    101.975  primary   ext3        boot
> 2        101.975   5098.754  primary   linux-swap
> 3       5098.755   7091.191  primary   ext3
> 4       7091.191 191600.624  extended
> 5       7091.222   9083.627  logical   ext3
> 6       9083.659  11076.064  logical   ext3
> (parted) mkpart logical ext3 11076.065 2288754
> Warning: You requested to create a partition at 11076.065-2288754.000Mb.
> The closest Parted can manage is 11076.095-191595.520Mb.
> OK/Cancel?
> 
> Any one have experience/ideas?

Yes.  Oh yes.  And I was so annoyed by the experience that I submitted a 
documentation erratum to RH about it (see 
<https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=155728>).  I'll 
detail it a bit here for the archives.

The short version is You Can't Do That.  Disk devices >2TB require gpt 
disk labels.  msdos disk labels (as you have above) can't handle devices 
of that size.  And neither grub nor lilo know how to boot from a gpt 
labelled device.  So, ATM, you cannot boot from a device >2TB.

Your only option at this point is to add in a new boot device and install 
to that.  Once you've done that, go ahead and use parted on your big 
array, being sure to 'mklabel gpt' before you make any partitions on it.

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University