Boot from a 3TB HDD?

[fkjensen]

Hi guys,

I have just installed ubuntu server on a 3 TB HDD, but it will not boot.
I have red some stuff about GPT and efi boot, but I am a bit confused (and yes, I am new at this linux stuff).
Any guide on how to set up the partitions so it will work?

The motherboard is an Intel D845GSEJT. It should support UEFI boot, but according to this:
http://www.intel.com/support/motherb...010355.htm#2TB
-----
Enabling support for 2 terabyte drives
If you are using a hard drive 2 terabytes or greater
in capacity, you must enable UEFI (Unified Extended Firmware Interface) in order
for your system to recognize the drive.

To enable UEFI:

1.During boot, enter the BIOS setup by pressing F2.
2.Go to the Boot menu.
3.Set UEFI Boot to Enable.
4.Press F10 to Save and Exit.
-----

I should enable it in the bios, but the option is not there. I have updated to the latest bios version.

Any help?

Best regards,
Frank

[darkod]

It says you only need that to recognize the disk as 3TB. Does it recognize it as 3TB? If it does, forget about it. And it's best to use legacy boot anyway, forget about the uefi boot.

With windows, you would have to use uefi boot since it needs that for gpt tables (and it needs a gpt table for a disk above 2TB), but with linux you can use legacy boot with gpt.

The only thing you need to be careful about, is that on gpt disks grub2 needs a small 1MiB partition with no filesystem and with the bios_grub flag set. Grub2 will put part of it's code there. Note: it does it automatically, you still install grub2 to the MBR, not that small partition.

For a 3TB disk it would also be good to put the boot files at front. There are two ways to do this: making a small / partition at front, or if you want / to be big and include everything, make a small /boot partition in front.

So, the order would be:
1. Check that the bios recognizes the disk as 3TB. Very important thing!!! If bios doesn't see it right, it will not present it right to the OS.
2. Make a gpt table on the disk (in case you already don't have one).
3. Make small 1MiB partition with no filesystem (raw format, no fat, no ntfs, no ext4, nothing). DO NOT format it with a filesystem. Put a bios_grub flag on it.
4. Make a small 500MB-1GB ext4 /boot partition, if you decided to go for that option.
5. Make / taking the rest of the disk...

[fkjensen]

Thanks for the extremely fast reply

The disk was recognized as 3TB during the install.
The rest of the stuff is where my linux skills fall a bit short (it seems I am always getting a bit confused, when it comes to partitioning in linux...)

How do I make a gpt table on the disk?

Once that is done, I guess I can maybe figure out the rest - maybe...

I was thinking of making a smallish (~20GB) / partition and then use the rest for /home, but a 1GB /boot and the rest for / would also work. Or maybe 1GB for /boot, 20GB for / and then the rest for /home...
Any pros and cons?
What's the recommended file system for these partitions? ext4?

~Frank

[darkod]

If you plan to run some services, like mysql databases, etc, note that by default they don't put the data in /home. So having a small / can be bad. And if you make small / at start there is no need for separate /boot.

I prefer doing partitioning with parted in terminal in live mode. So, boot the server first with the desktop live cd in live mode and open terminal. If that hdd is the only one, it will be /dev/sda. If not, change the following commands accordingly.

Use parted to manipulate the partitions:

sudo parted /dev/sda

Once in the parted prompt:

mklabel gpt #(new blank gpt table)
unit MiB #(change the display units to MiB)
mkpart GRUB 1 2 #(make small 1MiB partition between 1 and 2 with label GRUB)
set 1 bios_grub on #(set the bios_grub flag to ON on that partition)
mkpart ROOT 2 20482 #(make partition for / with size 20480MiB=20GiB)
mkpart HOME 20482 xxxxx #(make partition for /home between 20482 and the total number of MiB on the disk minus few)
quit #(quit parted)

You can get the total numbers of MiB of the disk after you changed the unit with:
print

on the parted prompt. Using print you can view the current info at all times. The disk details shown will show the total size in MiB if the current unit is MiB.

That should get you going. When making the server install use the partitions 2 and 3 as ext4, with mount points / and /home respectively. Do NOT make any changes on partitions 1, leave it as it is.

[fkjensen]

Thanks for the guide.
I didn't do it yet, but when I check the partitions during the install, I get something similar:



It isn't called bios_grub but biosgrub though. When I look at the details the boot flag is not set:



I doesn't look like I can change it...

Also, why are there two unused parts (they are small, yes, but why?)
And what's the 2nd partition (ext2) for?

I have used LVM on the 3rd partition. Is that ok?

Best regards,
Frank

[fkjensen]

Btw, don't I need a swap partition as well?

Best regards,
Frank

[darkod]

The biosgrub is fine, that's how the server installer shows it. The bootable flag is not the same, you see it says Use As: Reserved BIOS boot area. That should be fine.

The small 250MB partition was probably prepared to be /boot, because often when using LVM you have separate /boot outside the LVM. But you need to select it with Enter, change the Use As to ext4, and select mount point /boot.

You also need to "use" both LVs you have at the top. Select the root LV and set it as ext4 with mount point /. Then select the swap LV (that will be the swap), and select the Use As to swap area. Swap doesn't use mount point.

That should be it.

But before you start you might consider deleting partitions #2 and #3 and making a bigger ext4 partition for /boot, and then the rest of the space for the LVM. It's best to have little bit more in /boot than 250MB. Something like 500MB or 1GB.

[fkjensen]

Thanks.

One more thing, I am asked if it should install GRUB to the master boot record. Should I?

Ok, one more thing, I have not set anything up regarding GPT. Should I have done that or is it using GPT as standard (could be, I am not really understanding this properly...)?

Best regards,
Frank

[fkjensen]

Well I did install grub to the MBR, but it didn't boot...
My partitions are set up as:


What am I doing wrong? Is it the grub on the MBR or is it that I do not use GPT and if so, how do I set that up during the install? Or do I have to make a USB with the desktop version and do the "parted" suggestion above?

Best regards,
Frank

[darkod]

It looks good. Yes, the bootloader goes to the MBR. You are using gpt since partition #4 is 3TB. With msdos table the max partition size is around 2TB. So it can't be msdos.

You can also try this: Open the / partition and set the boot flag on it. Sometimes some motherboards need that even though ubuntu doesn't use it.