Handbook:AMD64/Blocks/Disks/ko

공간 분할
비록 이론적으로 리눅스 시스템을 저장할 디스크 전체를 사용할 수 있다고는 하지만, 실제로는 거의 불가능합니다. 대신, 전체 디스크 블록 장치를 더 작게 나누고, 더 관리하기 쉬운 블록 장치로 만들 수 있습니다. AMD64 시스템에서는, 파티션이라고 합니다. 현재 MBR과 GPT 두가지 분할 표준 기술이 있습니다.

MBR
MBR(주 부트 레코드) 설정은 시작 섹터 및 파티션의 길이, 그리고 다음의 파티션 형식을 지원하는 32비트 식별자를 사용합니다: 주, 확장, 논리. 주 파티션은 마스터 부트 레코드 자체에 저장한 정보를 지니고 있습니다. 마스터 부트 레코드는 매우 작으며(보통 512 바이트) 디스크의 맨 처음에 위치합니다. 공간이 작기 때문에 오직 네 개의 주 파티션만을 지원합니다(예를 들자면, 부터 까지).

더 많은 파티션을 지원하려면 주 파티션 중 하나를 확장 파티션으로 표시할 수 있습니다. 이 파티션은 논리 파티션(파티션 안의 파티션)을 보유할 수 있습니다.

각각의 파티션은 2 TB 크기로 제한됩니다(32 비트 식별자이기 때문에). 또한 MBR 설정에서는 백업 MBR을 제공하지 않기 때문에 프로그램이나 사용자가 MBR을 덮어쓰면, 모든 파티션 정보를 잃습니다.

GPT
GPT (GUID 파티션 테이블) 설정에선 파티션에 64비트 식별자를 사용합니다. 파티션 정보를 저장하는 위치는 512 바이트의 MBR보다 훨씬 크며, 파티션의 수량에 제한이 없습니다. 또한 파티션 사이즈도 훨씬 큰 제한 공간에 둘러쌓여있습니다(거의 8 ZB - 예, 제타바이트입니다).

운영 체제와 펌웨어의 시스템 프로그램 인터페이스가 (BIOS 대신) UEFI일 때, GPT는 MBR로 인한 호환성 문제가 일어나는 현 상황에서 단연 필수라 할 수 있습니다.

GPT는 또한 디스트의 마지막 부분에 백업 GPT를 보유하여 디스크 시작 부분의 주 GPT 손상을 복구할 수 있는 장점이 있습니다. GPT는 또한 CRC32 체크섬을 활용하여 헤더와 파티션 테이블의 오류를 감지합니다.

GPT냐 MBR이냐
From the description above, one might think that using GPT should always be the recommended approach. But there are a few caveats with this.

Using GPT on a BIOS-based computer works, but then one cannot dual-boot with a Microsoft Windows operating system. The reason is that Microsoft Windows will boot in EFI mode if it detects a GPT partition label.

Some buggy BIOSes or EFIs configured to boot in BIOS/CSM/legacy mode might also have problems with booting from GPT labeled disks. If that is the case, it might be possible to work around the problem by adding the boot/active flag on the protective MBR partition which has to be done through  (  understands the GPT tables and would not show the protective MBR partition).

In this case, launch  and toggle the flag using  on the first partition. Then write the changes to the disk and exit the   application:

UEFI 사용
When installing Gentoo on a system that uses UEFI to boot the operating system (instead of BIOS), then it is important that an EFI system partition is created. The instructions for  below contain the necessary pointers for this. The  notes don't, as   does not support GPT, which is the recommended (and often even only supported) partition table type for UEFI systems.

The EFI system partition also needs to be a FAT32 partition (or vfat as it is shown on Linux systems). The instructions at the end of this chapter use ext2 as the example file system for the partition. Make sure to use vfat, like so:

Advanced storage
The AMD64 Installation CDs provide support for LVM2. LVM2 increases the flexibility offered by the partitioning setup. During the installation instructions, we will focus on "regular" partitions, but it is still good to know LVM2 is supported as well.

Default partitioning scheme
Throughout the remainder of the handbook, the following partitioning scheme is used. If this suffices, then the reader can immediately jump to Default: Using parted to partition the disk or Alternative: Using fdisk to partition the disk. Both are partitioning tools,  is well known and stable,   is a bit more recent but supports partitions larger than 2TB).

Before going to the creation instructions, the first set of sections will describe in more detail how partitioning schemes can be created and what the common pitfalls are.

What is the BIOS boot partition
A BIOS boot partition is a very small (1 to 2 MB) partition in which boot loaders like GRUB2 can put additional data that doesn't fit in the allocated storage (a few hundred bytes in case of MBR) and cannot be placed elsewhere.

Such partitions are not always necessary, but considering the low space consumption and the difficulties we have with documenting the plethora of partitioning differences otherwise, it is recommended to create it in either case.

For completeness, the BIOS boot partition is needed when GPT partition layout is used with GRUB2, or when the MBR partition layout is used with GRUB2 when the first partition starts earlier than the 1 MB location on the disk.

Default: Using parted to partition the disk
In this chapter, we the example partition layout mentioned earlier in the instructions will be used:

Change the partition layout according to personal preference.

Viewing the current partition layout with parted
The  application offers a simple interface for partitioning the disks and supports very large partitions (more than 2 TB). Fire up  against the disk (in our example, we use ). It is recommended to ask  to use optimal partition alignment:

Alignment means that partitions are started on well-known boundaries within the disk, ensuring that operations on the disk from the operating system level (retrieve pages from the disk) use the least amount of internal disk operations. Misaligned partitions might require the disk to fetch two pages instead of one even if the operating system asked for a single page.

To find out about all options supported by parted, type  and press return.

Setting the GPT label
Most disks on x86/amd64 are prepared using an msdos label. Using, the command to put a GPT label on the disk is  :

To have the disk with MBR layout, use.

Removing all partitions with parted
If this isn't done yet (for instance through the  operation earlier, or because the disk is a freshly formatted one), first remove all existing partitions from the disk. Type  to view the current partitions, and   where NUMBER is the partition to remove.

Do the same for all other partitions that aren't needed. However, make sure to not make any mistakes here - parted executes the changes immediately (unlike  which stages them, allowing a user to "undo" his changes before saving or exiting fdisk).

Creating the partitions
Now create the partitions. Creating partitions with  isn't very difficult - all we need to do is inform parted about the following settings:


 * The partition type to use. This usually is primary. If the msdos partition label is used, keep in mind that there can be no more than 4 primary partitions. If more than 4 partitions ae needed, make one of the first four partitions extended and create logical partitions inside it.
 * The start location of a partition (which can be expressed in MB, GB, ...)
 * The end location of the partition (which can be expressed in MB, GB, ...)

First, tell parted that the size unit we work with is megabytes (actually mebibytes, abbreviated as MiB which is the "standard" notation, but we will use MB in the text throughout as it is much more common):

Now create a 2 MB partition that will be used by the GRUB2 boot loader later. Use the  command for this, and inform   to start from 1 MB and end at 3 MB (creating a partition of 2 MB in size).

Do the same for the boot partition (128 MB), swap partition (in the example, 512 MB) and the root partition that spans the remaining disk (for which the end location is marked as -1, meaning the end of the disk minus one MB, which is the farthest a partition can go).

When using the UEFI interface to boot the system (instead of BIOS), mark the boot partition as the EFI System Partition. Parted does this automatically when the boot option is set on the partition:

The end result looks like so:

Use the  command to exit parted.

Alternative: Using fdisk to partition the disk
The following parts explain how to create the example partition layout using. The example partition layout was mentioned earlier:

Change the partition layout according to personal preference.

Viewing the current partition layout
is a popular and powerful tool to split a disk into partitions. Fire up  against the disk (in our example, we use ):

Type to display the disk's current partition configuration:

This particular disk is configured to house seven Linux filesystems (each with a corresponding partition listed as "Linux") as well as a swap partition (listed as "Linux swap").

Removing all partitions with fdisk
First remove all existing partitions from the disk. Type to delete a partition. For instance, to delete an existing :

The partition has now been scheduled for deletion. It will no longer show up when printing the list of partitions (, but it will not be erased until the changes have been saved. This allows users to abort the operation if a mistake was made - in that case, type immediately and hit enter and the partition will not be deleted.

Repeatedly type to print out a partition listing and then type  and the number of the partition to delete it. Eventually, the partition table will be empty:

Now that the in-memory partition table is empty, we're ready to create the partitions.

Creating the BIOS boot partition
First create a very small BIOS boot partition. Type to create a new partition, then  to select a primary partition, followed by  to select the first primary partition. When prompted for the first sector, make sure it starts from 2048 (which is needed for the boot loader) and hit enter. When prompted for the last sector, type +2M to create a partition 2 Mbyte in size:

Mark the partition for EFI purposes:

Creating the boot partition
Now create a small boot partition. Type to create a new partition, then  to select a primary partition, followed by  to select the second primary partition. When prompted for the first sector, accept the default by hitting. When prompted for the last sector, type +128M to create a partition 128 Mbyte in size:

Now, when pressing, the following partition printout is displayed:

Type to toggle the bootable flag on a partition and select. After pressing again, notice that an * is placed in the "Boot" column.

Creating the swap partition
To create the swap partition, type to create a new partition, then  to tell fdisk to create a primary partition. Then type to create the third primary partition,. When prompted for the first sector, hit. When prompted for the last sector, type +512M (or any other size needed for the swap space) to create a partition 512MB in size.

After all this is done, type to set the partition type,  to select the partition just created and then type in 82 to set the partition type to "Linux Swap".

Creating the root partition
Finally, to create the root partition, type to create a new partition, then  to tell   to create a primary partition. Then type to create the fourth primary partition,. When prompted for the first sector, hit. When prompted for the last sector, hit to create a partition that takes up the rest of the remaining space on the disk. After completing these steps, typing should display a partition table that looks similar to this:

Saving the partition layout
To save the partition layout and exit, type.

With the partitions created, it is now time to put filesystems on them.