[CentOS] Centos 5 on Large Disks.

Tue Oct 23 15:35:33 UTC 2007
Ross S. W. Walker <rwalker at medallion.com>

Anup Shukla wrote:
> Peter Kjellstrom wrote:
> > On Tuesday 23 October 2007, Anup Shukla wrote:
> > ...
> >> I think its finally got into my head now. :)
> >>
> >>  From what i understand (after your replies and some more googling)
> >> GRUB cannot boot from gpt labeled drives.
> >> So no matter how i partition them, it just wont boot.
> > 
> > Correct.
> > 
> >> So finally, i am putting a 300G SATA to act as the "system" drive.
> >> Then use the other 750G's to be the big RAID 5 Volume (XFS)
> Yes, thought about it.
> But DELL PERC does not seem to be able to do that.
> That is atleast what i have found out till now.
> Wish it was possible.
> Just in case, if anyone knows better, please let me know.
> I have a Dell PE2950

Which Dell PERC they make dozens under that name?

If it is the PERC 5e then yes you can create multiple LUNs out of an

> > 
> > That will work. Another way is to see if the 
> raid-controller can present two 
> > volumes from your raid5, one small (for OS) and one big 
> (for gpt large fs). 
> > If this works then you'll get one device on which you can use msdos 
> > partitions and boot from and one (>2T) on which you use gpt 
> (or simply lvm 
> > directly on the device).

IMHO I would recommend using 2 internal drives with a software mirror
for the CentOS install and keep your external array completely out of
the OS install.

I use LVM for all volumes, use ext3 file system for the OS volumes, and
you can pick or choose the file system you want to use for your data
volumes, I'd probably stick with ext3 or maybe jfs if it wasn't too
cumbersome to get going.

My server disk config of choice in kickstart speak:

part raid.1 --noformat --onpart sda1
part raid.2 --noformat --onpart sdb1
part raid.3 --noformat --onpart sda2
part raid.4 --noformat --onpart sdb2

raid /boot --useexisting --fstype ext3 --level=RAID1 --device=md0 raid.1 raid.2
raid pv.1 --noformat --useexisting --fstype "physical volume (LVM)" --level=RAID1 --device=md1 raid.3 raid.4

volgroup CentOS --noformat --useexisting --pesize=32768 pv.1
logvol / --useexisting --fstype ext3 --name=root --vgname=CentOS --size=8192
logvol swap --useexisting --fstype swap --name=swap --vgname=CentOS --size=4096

That setup will yield an initial 100MB /boot, 8GB / and 4GB swap and leave the
rest of the space free for future use.

You can then create a separate VG out of your data array and sub-divide it into
smaller LVs formatted for the FS of choice.

Don't allocate all storage initially, just what you need to get started you can
always extend your volumes later relatively easily, but shrinking is far more


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