[CentOS] Re: Centos 5 on Large Disks.

[Scott Silva]

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!!!!