Install/Partitioning

Revision as of 23:10, November 18, 2014 by Drobbins (Talk | contribs)


Note

This is a template that is used as part of the Installation instructions which covers: the process of partitioning and filesystem creation. Templates are being used to allow multiple variant install guides that use most of the same re-usable parts.


Prepare Hard Disk

Introduction

In earlier times, there was only one way to boot a PC-compatible computer. All of our desktops and servers had a standard BIOS, all our hard drives used Master Boot Records, and were partitioned using the MBR partition scheme. And we liked it that way!

Then, along came EFI and UEFI, which are new-style firmware designed to boot systems, along with GPT partition tables to support disks larger than 2.2TB. All of the sudden, we had a variety of options to boot Linux systems, turning what once was a one-method-fits-all approach into something a lot more complex.

Let's take a moment to review the boot options available to you. This Install Guide uses, and recommends, the old-school method of BIOS booting and using an MBR. It works. There's nothing wrong with it. If your system disk is 2TB or smaller in size, it won't prevent you from using all of your disk's capacity, either.

But, there are some situations where the old-school method isn't optimal. If you have a system disk >2TB in size, then MBR partitions won't allow you to access all your storage. So that's one reason. Another reason is that there are some so-called "PC" systems out there that don't support BIOS booting anymore, and force you to use UEFI to boot.

Our recommendation is still to go old-school unless you have reason not to. We call this method the BIOS + GRUB (MBR) method. It's the traditional method of setting up a PC-compatible system to boot Linux.

If you need to use UEFI to boot, we recommend not using the MBR at all for booting, as some systems support this, but others don't. Instead, we recommend using UEFI to boot GRUB, which in turn will load Linux. We refer to this method as the UEFI + GRUB (GPT) method.

And yes, there are even more methods, some of which are documented on the Boot Methods page. We used to recommend a BIOS + GRUB (GPT) method but it is not consistently supported across a wide variety of hardware.

The big question is -- which boot method should you use? Here's how to tell.

Principle 1 - Old School
If you can reliably boot System Rescue CD and it shows you an initial light blue menu, you are booting the CD using the BIOS, and it's likely that you can thus boot Funtoo Linux using the BIOS. So, go old-school and use BIOS booting, unless you have some reason to use UEFI, such as having a >2.2TB system disk. In that case, see Principle 2, as your system may also support UEFI booting.
Principle 2 - New School
If you can reliably boot System Rescue CD and it shows you an initial black and white menu -- congratulations, your system is configured to support UEFI booting. This means that you are ready to install Funtoo Linux to boot via UEFI. Your system may still support BIOS booting, but just be trying UEFI first. You can poke around in your BIOS boot configuration and play with this.
What's the Big Difference between Old School and New School?
Here's the deal. If you go with old-school MBR partitions, your /boot partition will be an ext2 filesystem, and you'll use fdisk to create your MBR partitions. If you go with new-school GPT partitions and UEFI booting, your /boot partition will be a vfat filesystem, because this is what UEFI is able to read, and you will use gdisk to create your GPT partitions. And you'll install GRUB a bit differently. That's about all it comes down to, in case you were curious.

Old-School (MBR) Method

Note

Use this method if you are booting using your BIOS, and if your System Rescue CD initial boot menu was light blue.

Preparation

First, it's a good idea to make sure that you've found the correct hard disk to partition. Try this command and verify that /dev/sda is the disk that you want to partition:

# fdisk -l /dev/sda

Disk /dev/sda: 640.1 GB, 640135028736 bytes, 1250263728 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: gpt


#         Start          End    Size  Type            Name
 1         2048   1250263694  596.2G  Linux filesyste Linux filesystem

Now, it's recommended that you erase any existing MBR or GPT partition tables on the disk, which could confuse the system's BIOS at boot time. We do this using sgdisk:

Warning

This will make any existing partitions inaccessible! You are strongly cautioned and advised to backup any critical data before proceeding.

# sgdisk --zap-all /dev/sda

Creating new GPT entries.
GPT data structures destroyed! You may now partition the disk using fdisk or
other utilities.

This output is also nothing to worry about, as the command still succeded:

***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory. 
***************************************************************
Partitioning

Now we will use fdisk to create the MBR partition table and partitions:

# fdisk /dev/sda

Within fdisk, follow these steps:

Empty the partition table:

Command (m for help): o ↵

Create Partition 1 (boot):

Command (m for help): n ↵
Partition type (default p): 
Partition number (1-4, default 1): 
First sector: 
Last sector: +128M ↵

Create Partition 2 (swap):

Command (m for help): n ↵
Partition type (default p): 
Partition number (2-4, default 2): 
First sector: 
Last sector: +2G ↵
Command (m for help): t ↵ 
Partition number (1,2, default 2): 
Hex code (type L to list all codes): 82 ↵

Create the root partition:

Command (m for help): n ↵
Partition type (default p): 
Partition number (3,4, default 3): 
First sector: 
Last sector: 

Verify the partition table:

Command (m for help): p

Disk /dev/sda: 298.1 GiB, 320072933376 bytes, 625142448 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x82abc9a6

Device    Boot     Start       End    Blocks  Id System
/dev/sda1           2048    264191    131072  83 Linux
/dev/sda2         264192   4458495   2097152  82 Linux swap / Solaris
/dev/sda3        4458496 625142447 310341976  83 Linux

Write the parition table to disk:

Command (m for help): w

Your new MBR partition table will now be written to your system disk.

Partitioning Using gdisk

Notes Before We Begin

These install instructions assume you are installing Funtoo Linux to an empty hard disk using GUID partition tables (GPT). If you are installing Funtoo Linux on a machine where another OS is installed, or there is an existing Linux distribution on your system that you want to keep, then you will need to adapt these instructions to suit your needs.

If you are going to create a legacy MBR partition table instead of GUID/GPT, you will use the fdisk command instead of gdisk, and you will not need to create the GRUB boot loader partition. See the table under Partitioning Recommendations, in particular the MBR Block Device (fdisk) and MBR Code columns. fdisk works just like gdisk, but creates legacy MBR partition tables instead of the newer GPT/GUID partition tables.

Advanced users may be interested in the following topics:

Using gdisk

The first step after booting SystemRescueCd is to use gdisk to create GPT (also known as GUID) partitions, specifying the disk you want to use, which is typically /dev/sda, the first disk in the system:

# gdisk /dev/sda

You should find gdisk very similar to fdisk. Here is the partition table we want to end up with:

Command (? for help): p
Disk /dev/sda: 234441648 sectors, 111.8 GiB
Logical sector size: 512 bytes
Disk identifier (GUID): A4E5208A-CED3-4263-BB25-7147DC426931
Partition table holds up to 128 entries
First usable sector is 34, last usable sector is 234441614
Partitions will be aligned on 2048-sector boundaries
Total free space is 2014 sectors (1007.0 KiB)

Number  Start (sector)    End (sector)  Size       Code  Name
   1            2048          206847   500.0 MiB   8300  Linux filesystem
   2          206848          272383   32.0 MiB    EF02  BIOS boot partition
   3          272384         8660991   4.0 GiB     8200  Linux swap
   4         8660992       234441614   107.7 GiB   8300  Linux filesystem

Command (? for help): 

Above, you'll see that we have a 500 MiB boot partition, a 32 MiB "BIOS boot partition" (also known as the GRUB boot loader partition), 4 GiB of swap, and the remaining disk used by a 107.7 GiB root partition.

New-School (UEFI/GPT) Method

The gdisk commands to create a GPT partition table are as follows. Adapt sizes as necessary, although these defaults will work for most users. Start gdisk:

# gdisk

Within gdisk, follow these steps:

Create a new empty partition table (This will erase all data on the disk when saved):

Command: o ↵
This option deletes all partitions and creates a new protective MBR.
Proceed? (Y/N): y ↵

Create Partition 1 (boot):

Command: n ↵
Partition Number: 1 ↵
First sector: 
Last sector: +500M ↵
Hex Code: 

Create Partition 2 (swap):

Command: n ↵
Partition Number: 3 ↵
First sector: 
Last sector: +4G ↵
Hex Code: 8200 ↵

Create Partition 3 (root):

Command: n ↵
Partition Number: 4 ↵
First sector: 
Last sector:  (for rest of disk)
Hex Code: 

Along the way, you can type "p" and hit Enter to view your current partition table. If you make a mistake, you can type "d" to delete an existing partition that you created. When you are satisfied with your partition setup, type "w" to write your configuration to disk:

Write Partition Table To Disk:

Command: w ↵
Do you want to proceed? (Y/N): Y ↵

The partition table will now be written to disk and gdisk will close.

Now, your GPT/GUID partitions have been created, and will show up as the following block devices under Linux:

  • /dev/sda1, which will be used to hold the /boot filesystem,
  • /dev/sda2, which will be used for swap space, and
  • /dev/sda3, which will hold your root filesystem.

Creating filesystems

Before your newly-created partitions can be used, the block devices need to be initialized with filesystem metadata. This process is known as creating a filesystem on the block devices. After filesystems are created on the block devices, they can be mounted and used to store files.

You will not create a filesystem on your swap partition, but will initialize it using the mkswap command so that it can be used as disk-based virtual memory. Then we'll run the swapon command to make your newly-initialized swap space active within the live CD environment, in case it is needed during the rest of the install process.

Note that we will not create a filesystem on the GRUB boot loader partition, as GRUB writes binary data directly to that partition when the boot loader is installed, which we'll do later.

You can see the commands you will need to type below. Like the rest of this document, it assumes that you are using a GPT partitioning scheme. If you are using MBR, your root filesystem will likely be created on /dev/sda3 instead and you will need to adjust the target block devices. If you are following our recommendations, then simply do this:

We generally recommend ext4 or XFS root filesystems. This tutorial assumes the use of ext4. If you want to use XFS, then be sure that your /etc/fstab file reflects this.

Warning

When deploying an OpenVZ host, please use ext4 exclusively. The Parallels development team tests extensively with ext4, and modern versions of openvz-rhel6-stable are not compatible with XFS, and you may experience kernel bugs.

To use ext4 as your root filesystem:

# mke2fs -t ext2 /dev/sda1 
# mkfs.ext4 /dev/sda3
# mkswap /dev/sda2
# swapon /dev/sda2

To use XFS as your root filesystem:

# mke2fs -t ext2 /dev/sda1 
# mkfs.xfs /dev/sda3
# mkswap /dev/sda2
# swapon /dev/sda2

Mounting filesystems

Mount the newly-created filesystems as follows, creating /mnt/funtoo as the installation mount point:

# mkdir /mnt/funtoo
# mount /dev/sda3 /mnt/funtoo
# mkdir /mnt/funtoo/boot
# mount /dev/sda1 /mnt/funtoo/boot

Optionally, if you have a separate filesystem for /home or anything else:

# mkdir /mnt/funtoo/home
# mount /dev/sda4 /mnt/funtoo/home

If you have /tmp or /var/tmp on a separate filesystem, be sure to change the permissions of the mount point to be globally-writeable after mounting, as follows:

# chmod 1777 /mnt/funtoo/tmp