[CentOS] Re: Centos 5 on Large Disks.

Scott Silva ssilva at sgvwater.com
Tue Oct 23 15:15:22 UTC 2007

on 10/23/2007 2:06 AM Anup Shukla spake the following:
> James A. Peltier wrote:
>> James A. Peltier wrote:
>>> Anup Shukla wrote:
>>>> Hi All,
>>>> Sorry if this has been answered many times.
>>>> But i have been going through a lot of pages (via google search).
>>>> The more i search, the more its confusing me.
>>>> I have a server with 6 (750G each) SATA disks with H/W Raid 5.
>>>> I plan to allocate the space as follows
>>>> swap 8G
>>>> /boot 100M
>>>> / 20G
>>>> -- and remaining space to /data{1,2,3,N} (equal sizes)
>>>> However after the installation and reboot, i got an error about bad 
>>>> partition for /data8
>>>> I had hit the 2T limit.
>>>> Then i found this page at 
>>>> http://www.knowplace.org/pages/howtos/linux_large_filesystems_support.php 
>>>> which speaks of using Parted/LVM2 and XFS.
>>>> If i understand this correctly,
>>>> I need to have 1 disk to host the CentOS installation.
>>>> And i can use the other 5 disks in a RAID array
>>>> (label type gpt...)
>>>> Is it not possible to partition and use the existing RAID 5 volume?
>>>> I really am not sure about how to proceed for this big disk problem.
>>>> Any ideas/links will really help.
>>>> Thank you.
>>>> Regards,
>>>> A.S
>>>> _______________________________________________
>>>> CentOS mailing list
>>>> CentOS at centos.org
>>>> http://lists.centos.org/mailman/listinfo/centos
>>> My understanding is that grub and lilo are not able to boot off of 
>>> GPT labeled disks currently.  Given the size of currently available 
>>> disks, this will probably change soon, however, for now you need a 
>>> small partition to boot a large disk.
>> sorry, a bit quick off the trigger, but essentially, if you wanted to 
>> use a single RAID-5 volume of this size (even if you configured it as 
>> you said) the GPT label for the volume would be what gets you cuz of 
>> the boot loader.
>> The use of LVM and XFS, just have to do with the way they handle 
>> larger disks.  With LVM you can lay out the disks in a bit more fine 
>> tuned manner that allows you go get around some limitations in certain 
>> file systems.  XFS is just recommended because it is a very good 
>> performer and was meant to handle large file systems from its 
>> inception.  Feel free to use JFS, ReiserFS or your local don-juan-ho 
>> file system you like
> 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.
> 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, i lose if the 300G fails, but i think i can do something about that 
> later.
You did say a hardware raid5 right?
You just need to have the /boot partition at the beginning of the array, and 
your raid card should have some sort of carving feature. You just need to make 
sure you have multi-lun support going, and with your kernel and initrd in the 
boot partition you should be able to boot.

MailScanner is like deodorant...
You hope everybody uses it, and
you notice quickly if they don't!!!!

More information about the CentOS mailing list