On 05/10/2014 07:22 PM, Dennis Jacobfeuerborn wrote:
> On 10.05.2014 19:17, Dennis Jacobfeuerborn wrote:
>> On 10.05.2014 18:36, CS_DBA wrote:
>>> Hi All;
>>>
>>> I have a new server we're setting up that supports EFI or Legacy in the bios
>>>
>>> I am a solid database guy but my SA skills are limited to what I need to
>>> get by
>>>
>>> 1) I used EFI because I wanted to create a raid 10 array with 6 4TB
>>> drives and apparently I cannot setup gpt partitions via parted in legacy
>>> mode (at least that's what I've read - is this true?)
>>
>> When you say legacy mode do you mean BIOS or the CSM ("Compatibility
>> Support Module") of the UEFI firmware?
>>
>> BIOS cannot boot from GPT partition but the CSM mode of the UEFI
>> firmware should be able to. You really want to go with plain UEFI though
>> if your system supports it.
>>
>>> 2) I installed the OS on 2 500GB drives, I used to do all my installs
>>> with software RAID (mirrored) without LVM as follows:
>>> - create 2 raid partitions (one on each drive) for swap, /boot and /
>>> - create a raid1 device for each set of partitions above
>>>
>>> The installer would not let me proceed without a /boot/efi partition I
>>> tried to create a raid partition on each drive for this and create a
>>> /boot/efi raid disk but when I doit this way in the installer I no
>>> longer see the "EFI SYSTEM Partition" as an option for the filesystem
>>> type so this did not work either.
>>>
>>> I ended up doing hardware raid for the OS drives and software raid for
>>> the 6 4TB data drives. It works but I prefer to do software raid for
>>> everything so we ca have standard methods of monitoring for bad drives.
>>>
>>> Is there a way to setup software raid with EFI?
>>
>> No. The UEFI Firmware needs to access to this partition before it can
>> boot the OS so anything that needs to have the OS running (like a
>> software raid) cannot work.
>> What you can do is create the partition on both disks, point the
>> installer to only the first disk and then later copy the files over to
>> the partition on the other disk so that if the first disk dies you can
>> still boot using the second one.
>> The partition can be tiny (just a couple of megabytes), should be the
>> first partition on the disk (though I think this is not strictly
>> necessary), should be formatted as FAT32, and should be given a type
>> GUID of "C12A7328-F81F-11D2-BA4B-00A0C93EC93B" which means "EFI System
>> partition" so that the UEFI firmware can find it.
>>
>> You *should* be able to create the other partitions (including /boot) as
>> software raid though I've not done this myself yet so I'm not 100%
>> certain on that.
>
> Just to give you an idea what a "couple of megabytes" means this is what
> is stored on my EFI partition right now:
>
> [root at nexus EFI]# du -csh /boot/efi/EFI/*
> 658K /boot/efi/EFI/Boot
> 7,8M /boot/efi/EFI/fedora
> 244K /boot/efi/EFI/fedora15
> 18M /boot/efi/EFI/Microsoft
> 247K /boot/efi/EFI/redhat
> 27M total
>
> That's with four different OS installations so for a non-dual-boot
> system something like 50-100MB should be plenty.
>
> Regards,
> Dennis
>
Is there any guide/tutorial/step-by-step how to install GPT-UEFI-CentOS
6.5? I can not seam to locate one.
--
Ljubomir Ljubojevic
(Love is in the Air)
PL Computers
Serbia, Europe
StarOS, Mikrotik and CentOS/RHEL/Linux consultant