Handbook:X86/Blocks/Disks
Tablice partycji
Mimo, że teoretycznie jest możliwe użycie czystego, niepodzielonego na partycje dysku dla systemu Linuks (na przykład podczas tworzenia btrfs RAID), w praktyce prawie nigdy się tego nie robi. Zamiast tego, dyski są podzielone na mniejsze, łatwiejsze w zarządzaniu części. W architekturze x86 są one nazywane partycjami. Obecnie stosowane są dwie standardowe technologie partycjonowania: MBR i GPT.
GPT
GPT (Tablica Partycji GUID) używa 64-bitowych identyfikatorów dla partycji. Obszar pamięci w którym przechowuje informacje o partycjach jest znacznie większy, niż zastosowane 512 bajtów w Głównym Rekordzie Rozruchowym (MBR), co oznacza praktyczny brak limitów ilości partycji dla dysku GPT. Dodatkowo, rozmiar pojedyńczej partycji ma o wiele wiekszy limit (prawie 8 ZiB - tak, zettabajtów).
Gdy interfejs oprogramowania systemowego między systemem operacyjnym a oprogramowaniem układowym to UEFI (zamiast BIOS), GPT jest prawie obowiązkowe, ponieważ pojawią się problemy ze zgodnością z MBR.
GPT wykorzystuje również sumy kontrolne i redundancję. Za pomocą sumy kontrolnej CRC32 sprawdza błędy w tablicach partycji i nagłówka oraz posiada kopię zapasową GPT na końcu dysku. Można ją użyć do odzyskania uszkodzenego podstawowego GPT w pobliżu początku dysku.
There are a few caveats regarding GPT:
- 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 UEFI mode if it detects a GPT partition label.
- Some buggy (old) motherboard firmware configured to boot in BIOS/CSM/legacy mode might also have problems with booting from GPT labeled disks.
MBR
MBR (Master Boot Record) to struktura, która używa 32-bitowych identyfikatorów dla sektora startowego i długości partycji, wspierająca trzy typy partycji: podstawowe, rozszerzone i logiczne. Informacja o partycjach podstawowych jest zapisana w samym Głównym Rekordzie Rozruchowym - bardzo mały rozmiar (zazwyczaj 512 bajtów) na samym początku dysku. Z powodu bardzo małego rozmiaru, są wspierane tylko cztery partycje podstawowe (dla przykładu, /dev/sda1 do /dev/sda4).
Aby posiadać wiecej partycji, jedna z podstawowych musi być oznaczona jako partycja rozszerzona. Taka partycja może zawierać inne partycje logiczne (partycje w partycji).
Chociaż wciąż wspierana przez większość producentów, ta tablica partycji jest uważana za przestarzałą. Jeżeli nie pracujesz z sprzętem z przed 2010 roku, najlepiej partycjonować dysk używając Tablicy Patrtycji GUID. Czytelnicy, którzy nadal muszą korzystać z MBR, powinni zapoznać się z następującymi informacjami:
- Większość płyt głównych wyprodukowanych po 2010 roku uznaje MBR za przestarzały (wspierany, lecz nie idealny) tryb rozruchowy.
- Z powodu użycia 32-bitowych identyfikatorów, MBR nie potrafi obsłużyć dysków twardych o pojemności większej od 2TB.
- Bez użycia partycji rozszerzonej, MBR wspiera utworzenie maksymalnie czterech partycji.
- System partycjonowania MBR nie zapewnia kopii zapasowej, więc jeżeli aplikacja lub użytkownik nadpiszą MBR, wszystkie informacje o partycjach zostaną utracone.
Autorzy Podręcznika rekomendują użycie GPT ilekroć to możliwe dla instalacji Gentoo.
Advanced storage
The official Gentoo boot media provides support for Logical Volume Manager (LVM). LVM can combine physical volumes such as partitions or disks into volume groups. Volume groups are more flexible than partitions and can be used to define RAID groups or caches on fast SSDs for slow HDs. Although usage is not covered in the handbook, LVM is fully supported in Gentoo.
Domyślny schemat partycjonowania
Throughout the remainder of the handbook, we will discuss and explain two cases:
- UEFI firmware with GUID Partition Table (GPT) disk.
- MBR DOS/legacy BIOS firmware with a MBR partition table disk.
While it is possible to mix and match boot types with certain motherboard firmware, mixing goes beyond the intention of the handbook. As previously stated, it is strongly recommended for installations on modern hardware to use UEFI boot with a GPT disklabel disk.
The following partitioning scheme will be used as a simple example layout.
The first row of the following table contains exclusive information for either a GPT disklabel or a MBR DOS/legacy BIOS disklabel. When in doubt, proceed with GPT, since x86 machines manufactured after the year 2010 generally support UEFI firmware and GPT boot sector.
| Partition | Filesystem | Size | Description |
|---|---|---|---|
| /dev/sda1 | fat32 File system required for the EFI System Partition, which is always associated with a GPT disklabel. | 1 GiB | EFI System Partition details. Applicable to system firmware supporting an UEFI implementation. This is typically the case for systems manufactured around the year 2010 to the present. |
| ext4 Recommended file system for the boot partition of a MBR partition table, which is used in conjunction with older firmware limited to the DOS/legacy BIOS disklabel. | MBR DOS/legacy BIOS boot partition details. Applicable to legacy BIOS machine firmware. Systems of this type were typically manufactured <u>before</u> the year 2010 and have generally phased out of production. | ||
| /dev/sda2 | linux-swap | RAM size * 2 | Swap partition details. |
| /dev/sda3 | xfs | Remainder of the disk The selected profile, additional partitions (optional), and system purpose add complexities for appropriately sizing the rootfs, therefore the Handbook authors cannot offer a 'one-size-fits-all' suggestion for the rootfs partition.</br></br> When Gentoo is the only operating system using the disk, selecting the remainder of the disk is the safest and suggested choice. | Root partition details. |
If this suffices as information, the advanced reader can directly skip ahead to the actual partitioning.
Both fdisk and parted are partitioning utilities included within the official Gentoo live image environments. fdisk is well known, stable, and handles both MBR and GPT disks. parted was one of the first Linux block device management utilities to support GPT partitions. It can be used as an alternative to fdisk if the reader prefers, however the handbook will only provide instructions for fdisk, since since it is commonly available on most Linux environments.
Before going to the creation instructions, the first set of sections will describe in more detail how partitioning schemes can be created and mention some common pitfalls.
Designing a partition scheme
How many partitions and how big?
The design of disk partition layout is highly dependent on the demands of the system and the file system(s) applied to the device. If there are lots of users, then it is advised to have /home on a separate partition which will increase security and make backups and other types of maintenance easier. If Gentoo is being installed to perform as a mail server, then /var should be a separate partition as all mails are stored inside the /var directory. Game servers may have a separate /opt partition since most gaming server software is installed therein. The reason for these recommendations is similar to the /home directory: security, backups, and maintenance.
In most situations on Gentoo, /usr and /var should be kept relatively large in size. /usr hosts the majority of applications available on the system and the Linux kernel sources (under /usr/src). By default, /var hosts the Gentoo ebuild repository (located at /var/db/repos/gentoo) which, depending on the file system, generally consumes around 650 MiB of disk space. This space estimate excludes the /var/cache/distfiles and /var/cache/binpkgs directories, which will gradually fill with source files and (optionally) binary packages respectively as they are added to the system.
How many partitions and how big very much depends on considering the trade-offs and choosing the best option for the circumstance. Separate partitions or volumes have the following advantages:
- Choose the best performing filesystem for each partition or volume.
- The entire system cannot run out of free space if one defunct tool is continuously writing files to a partition or volume.
- If necessary, file system checks are reduced in time, as multiple checks can be done in parallel (although this advantage is realized more with multiple disks than it is with multiple partitions).
- Security can be enhanced by mounting some partitions or volumes read-only,
nosuid(setuid bits are ignored),noexec(executable bits are ignored), etc.
However, multiple partitions have certain disadvantages as well:
- If not configured properly, the system might have lots of free space on one partition and little free space on another.
- A separate partition for /usr/ may require the administrator to boot with an initramfs to mount the partition before other boot scripts start. Since the generation and maintenance of an initramfs is beyond the scope of this handbook, we recommend that newcomers do not use a separate partition for /usr/.
- There is also a 15-partition limit for SCSI and SATA unless the disk uses GPT labels.
Installations that intend to use systemd as the service and init system must have the /usr directory available at boot, either as part of the root filesystem or mounted via an initramfs.
What about swap space?
| RAM size | Suspend support? | Hibernation support? |
|---|---|---|
| 2 GB or less | 2 * RAM | 3 * RAM |
| 2 to 8 GB | RAM amount | 2 * RAM |
| 8 to 64 GB | 8 GB minimum, 16 maximum | 1.5 * RAM |
| 64 GB or greater | 8 GB minimum | Hibernation not recommended! Hibernation is not recommended for systems with very large amounts of memory. While possible, the entire contents of memory must be written to disk in order to successfully hibernate. Writing tens of gigabytes (or worse!) out to disk can can take a considerable amount of time, especially when rotational disks are used. It is best to suspend in this scenario. |
There is no perfect value for swap space size. The purpose of the space is to provide disk storage to the kernel when internal dynamic memory (RAM) is under pressure. A swap space allows for the kernel to move memory pages that are not likely to be accessed soon to disk (swap or page-out), which will free memory in RAM for the current task. Of course, if the pages swapped to disk are suddenly needed, they will need to be put back in memory (page-in) which will take considerably longer than reading from RAM (as disks are very slow compared to internal memory).
When a system is not going to run memory intensive applications or has lots of RAM available, then it probably does not need much swap space. However do note in case of hibernation that swap space is used to store the entire contents of memory (likely on desktop and laptop systems rather than on server systems). If the system requires support for hibernation, then swap space larger than or equal to the amount of memory is necessary.
As a general rule for RAM amounts less than 4 GB, the swap space size is recommended to be twice the internal memory (RAM). For systems with multiple hard disks, it is wise to create one swap partition on each disk so that they can be utilized for parallel read/write operations. The faster a disk can swap, the faster the system will run when data in swap space must be accessed. When choosing between rotational and solid state disks, it is better for performance to put swap on the solid state hardware.
It is worth noting that swap files can be used as an alternative to swap partitions; this is mostly helpful for systems with very limited disk space.
Korzystanie z UEFI
Podczas instalacji Gentoo na systemie wykorzystującym interfejs UEFI (zamiast BIOS) do uruchomienia systemu operacyjnego, bardzo ważne jest utworzenie Partycji Systemu EFI (ESP). Poniższe instrukcje dla parted zawierają niezbędne wskazówki, aby prawidłowo wykonać tą operację.
The ESP must be a FAT variant (sometimes shown as vfat on Linux systems). The official UEFI specification denotes FAT12, 16, or 32 filesystems will be recognized by the UEFI firmware, although FAT32 is recommended for the ESP. After partitioning, format the ESP accordingly:
root #mkfs.fat -F 32 /dev/sda1If the ESP is not formatted with a FAT variant, the system's UEFI firmware will not find the bootloader (or Linux kernel) and will most likely be unable to boot the system!
Czym jest partycja BIOS boot?
Partycja BIOS boot to bardzo mała partycja (o rozmiarze 1 do 2 MB) w której programy rozruchowe jak GRUB2 mogą przechowywać dodatkowe dane, które nie zmieszczą się w zaalokowanej pamięci (w przypadku MBR kilkaset bajtów) i nie mogą być zamieszczone w innym miejscu.
Partitioning the disk with GPT for UEFI
The following parts explain how to create an example partition layout for a single GPT disk device which will conform to the UEFI Specification and Discoverable Partitions Specification (DPS). DPS is a specification provided as part of the Linux Userspace API (UAPI) Group Specification and is recommended, but entirely optional. The specifications are implemented using the fdisk utility, which is part of the sys-apps/util-linux package.
The table provides a recommended defaults for a trivial Gentoo installation. Additional partitions can be added according to personal preference or system design goals.
| Device path (sysfs) | Mount point | File system | DPS UUID (Type-UUID) | Description |
|---|---|---|---|---|
| /dev/sda1 | /efi | vfat | c12a7328-f81f-11d2-ba4b-00a0c93ec93b | EFI system partition (ESP) details. |
| /dev/sda2 | N/A. Swap is not mounted to the filesystem like a device file. | 0657fd6d-a4ab-43c4-84e5-0933c84b4f4f | Swap partition details. | |
| /dev/sda3 | / | xfs | 44479540-f297-41b2-9af7-d131d5f0458a | Root partition details. |
Viewing the current partition layout
fdisk is a popular and powerful tool to split a disk into partitions. Fire up fdisk against the disk (in our example, we use /dev/sda):
root #fdisk /dev/sdaUse the p key to display the disk's current partition configuration:
Command (m for help):pDisk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: HGST HTS721010A9 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Disk identifier: 3E56EE74-0571-462B-A992-9872E3855D75 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Device Start End Sectors Size Type /dev/sda1 2048 2099199 2097152 1G EFI System /dev/sda2 2099200 10487807 8388608 4G Linux swap /dev/sda3 10487808 1953523711 1943035904 926.5G Linux root (x86-64)
This particular disk was configured to house two Linux filesystems (each with a corresponding partition listed as "Linux") as well as a swap partition (listed as "Linux swap").
Creating a new disklabel / removing all partitions
Pressing the g key will instantly remove all existing disk partitions and create a new GPT disklabel:
Command (m for help):gCreated a new GPT disklabel (GUID: 3E56EE74-0571-462B-A992-9872E3855D75).
Alternatively, to keep an existing GPT disklabel (see the output of p above), consider removing the existing partitions one by one from the disk. Press d to delete a partition. For instance, to delete an existing /dev/sda1:
Command (m for help):dPartition number (1-4): 1
The partition has now been scheduled for deletion. It will no longer show up when printing the list of partitions (p, 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, press q immediately and hit Enter and the partition will not be deleted.
Repeatedly press p to print out a partition listing and then press d and the number of the partition to delete it. Eventually, the partition table will be empty:
Command (m for help):pDisk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: HGST HTS721010A9 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Disk identifier: 3E56EE74-0571-462B-A992-9872E3855D75
Now that the in-memory partition table is empty, we're ready to create the partitions.
Creating the EFI System Partition (ESP)
A smaller ESP is possible but not recommended, especially given it may be shared with other OSes.
First create a small EFI system partition, which will also be mounted as /boot. Type n to create a new partition, followed by 1 to select the first partition. When prompted for the first sector, make sure it starts from 2048 (which may be needed for the boot loader) and hit Enter. When prompted for the last sector, type +1G to create a partition 1 GByte in size:
Command (m for help):nPartition number (1-128, default 1): 1
First sector (2048-1953525134, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-1953525134, default 1953523711): +1G
Created a new partition 1 of type 'Linux filesystem' and of size 1 GiB.
Partition #1 contains a vfat signature.
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Do you want to remove the signature? [Y]es/[N]o: Y
The signature will be removed by a write command.
Mark the partition as an EFI system partition:
Command (m for help):tSelected partition 1 Partition type or alias (type L to list all): 1 Changed type of partition 'Linux filesystem' to 'EFI System'.
Optionally, to have the ESP conform to the Discoverable System Partition (DSP) specification, switch to expert mode and perform the following extra step to set the partition's UUID:
Command (m for help):xExpert command (m for help):uSelected partition 1 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> New UUID (in 8-4-4-4-12 format): c12a7328-f81f-11d2-ba4b-00a0c93ec93b Partition UUID changed from 10293DC1-DF6C-4443-8ACF-C756B81B4767 to C12A7328-F81F-11D2-BA4B-00A0C93EC93B.
Press the r key to return to the main menu:
Expert command (m for help):r</div> <div lang="en" dir="ltr" class="mw-content-ltr"> Command (m for help):
Creating the swap partition
Next, to create the swap partition, press n to create a new partition, then press 2 to create the second partition, /dev/sda2. When prompted for the first sector, hit Enter. When prompted for the last sector, type +4G (or any other size needed for the swap space) to create a partition 4 GiB in size.
Command (m for help):nPartition number (2-128, default 2):
First sector (2099200-1953525134, default 2099200):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2099200-1953525134, default 1953523711): +4G
Created a new partition 2 of type 'Linux filesystem' and of size 4 GiB.
After this, press t to set the partition type, 2 to select the partition just created and then type in 19 to set the partition type to "Linux Swap".
Command (m for help):tPartition number (1,2, default 2): 2 Partition type or alias (type L to list all): 19 Changed type of partition 'Linux filesystem' to 'Linux swap'.
Optionally, to have the swap partition conform to the Discoverable System Partition (DSP) specification, switch to expert mode and perform the following extra step to set the partition's UUID:
Command (m for help):xExpert command (m for help):uPartition number (1,2, default 2): 2 Selected partition 2 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> New UUID (in 8-4-4-4-12 format): 0657fd6d-a4ab-43c4-84e5-0933c84b4f4f Partition UUID changed from 7529CDF6-9482-4497-B021-576745648B2A to 0657FD6D-A4AB-43C4-84E5-0933C84B4F4F..
Press the r key to return to the main menu:
Expert command (m for help):r</div> <div lang="en" dir="ltr" class="mw-content-ltr"> Command (m for help):
Creating the root partition
Finally, to create the root partition, press n to create a new partition, and then press 3 to create the third partition: /dev/sda3. When prompted for the first sector, press Enter. When prompted for the last sector, hit Enter to create a partition that takes up the rest of the remaining space on the disk.
Command (m for help):nPartition number (3-128, default 3): 3
First sector (10487808-1953525134, default 10487808):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (10487808-1953525134, default 1953523711):
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Created a new partition 3 of type 'Linux filesystem' and of size 926.5 GiB..
Setting the root partition's type to "Linux root (x86-64)" is not required and the system will function normally if it is set to the "Linux filesystem" type. This filesystem type is only necessary for cases where a bootloader that supports it (i.e. systemd-boot) is used and a fstab file is not wanted.
After creating the root partition, press t to set the partition type, 3 to select the partition just created, and then type in 23 to set the partition type to "Linux Root (x86-64)".
Command(m for help):tPartition number (1-3, default 3): 3 Partition type or alias (type L to list all): 23 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Changed type of partition 'Linux filesystem' to 'Linux root (x86-64)'
Optionally, to have the root partition conform to the Discoverable System Partition (DSP) specification, switch to expert mode and perform the following extra step to set the partition's UUID:
Command (m for help):xExpert command (m for help):uPartition number (1-3, default 3): 3 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> New UUID (in 8-4-4-4-12 format): 4f68bce3-e8cd-4db1-96e7-fbcaf984b709 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Partition UUID changed from 40465382-FA2A-4846-9827-640821CC001F to 4F68BCE3-E8CD-4DB1-96E7-FBCAF984B709.
Press the r key to return to the main menu:
Expert command (m for help):r</div> <div lang="en" dir="ltr" class="mw-content-ltr"> Command (m for help):
After completing these steps, pressing p should display a partition table that looks similar to the following:
Command (m for help):pDisk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: HGST HTS721010A9 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: gpt Disk identifier: 3E56EE74-0571-462B-A992-9872E3855D75 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Device Start End Sectors Size Type /dev/sda1 2048 2099199 2097152 1G Linux filesystem /dev/sda2 2099200 10487807 8388608 4G Linux swap /dev/sda3 10487808 1953523711 1943035904 926.5G Linux root (x86-64) </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Filesystem/RAID signature on partition 1 will be wiped.
Saving the partition layout
Press w to save the partition layout and exit the fdisk utility:
Command (m for help):wThe partition table has been altered. Calling ioctl() to re-read partition table. Syncing disks.
With partitions now available, the next installation step is to fill them with filesystems.
Partitioning the disk with MBR for BIOS / legacy boot
The following table provides a recommended partition layout for a trivial MBR DOS / legacy BIOS boot installation. Additional partitions can be added according to personal preference or system design goals.
| Device path (sysfs) | Mount point | File system | DPS UUID (PARTUUID) | Description |
|---|---|---|---|---|
| /dev/sda1 | /boot | ext4 | N/A | MBR DOS / legacy BIOS boot partition details. |
| /dev/sda2 | N/A. Swap is not mounted to the filesystem like a device file. | 0657fd6d-a4ab-43c4-84e5-0933c84b4f4f | Swap partition details. | |
| /dev/sda3 | / | xfs | 44479540-f297-41b2-9af7-d131d5f0458a | Root partition details. |
Change the partition layout according to personal preference.
Viewing the current partition layout
Fire up fdisk against the disk (in our example, we use /dev/sda):
root #fdisk /dev/sdaUse the p key to display the disk's current partition configuration:
Command (m for help):pDisk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: HGST HTS721010A9 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0xf163b576 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Device Boot Start End Sectors Size Id Type /dev/sda1 * 2048 2099199 2097152 1G 83 Linux /dev/sda2 2099200 10487807 8388608 4G 82 Linux swap / Solaris /dev/sda3 10487808 1953525167 1943037360 926.5G 83 Linux
This particular disk was until now configured to house two Linux filesystems (each with a corresponding partition listed as "Linux") as well as a swap partition (listed as "Linux swap"), using a GPT table.
Creating a new disklabel / removing all partitions
Pressing o will instantly remove all existing disk partitions and create a new MBR disklabel (also named DOS disklabel):
Command (m for help):oCreated a new DOS disklabel with disk identifier 0xf163b576. The device contains 'gpt' signature and it will be removed by a write command. See fdisk(8) man page and --wipe option for more details.
Alternatively, to keep an existing DOS disklabel (see the output of p above), consider removing the existing partitions one by one from the disk. Press d to delete a partition. For instance, to delete an existing /dev/sda1:
Command (m for help):dPartition number (1-4): 1
The partition has now been scheduled for deletion. It will no longer show up when printing the list of partitions (p, 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 q immediately and hit Enter and the partition will not be deleted.
Repeatedly press p to print out a partition listing and then press d and the number of the partition to delete it. Eventually, the partition table will be empty:
Command (m for help):pDisk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: HGST HTS721010A9 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0xf163b576
The disk is now ready to create new partitions.
Creating the boot partition
First, create a small partition which will be mounted as /boot. Press n to create a new partition, followed by p for a primary partition and 1 to select the first primary partition. When prompted for the first sector, make sure it starts from 2048 (which may be needed for the boot loader) and press Enter. When prompted for the last sector, type +1G to create a partition 1 GB in size:
Command (m for help):nPartition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-1953525167, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-1953525167, default 1953525167): +1G
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Created a new partition 1 of type 'Linux' and of size 1 GiB.
Mark the partition as bootable by pressing the a key and pressing Enter:
Command (m for help):aSelected partition 1 The bootable flag on partition 1 is enabled now.
Note: if more than one partition is available on the disk, then the partition to be flagged as bootable will have to be selected.
Creating the swap partition
Next, to create the swap partition, press n to create a new partition, then p, then type 2 to create the second primary partition, /dev/sda2. When prompted for the first sector, press Enter. When prompted for the last sector, type +4G (or any other size needed for the swap space) to create a partition 4GB in size.
Command (m for help):nPartition type
p primary (1 primary, 0 extended, 3 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (2-4, default 2): 2
First sector (2099200-1953525167, default 2099200):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2099200-1953525167, default 1953525167): +4G
Created a new partition 2 of type 'Linux' and of size 4 GiB.
After all this is done, press t to set the partition type, 2 to select the partition just created and then type in 82 to set the partition type to "Linux Swap".
Command (m for help):tPartition number (1,2, default 2): 2 Hex code (type L to list all codes): 82 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Changed type of partition 'Linux' to 'Linux swap / Solaris'.
Creating the root partition
Finally, to create the root partition, press n to create a new partition. Then press p and 3 to create the third primary partition, /dev/sda3. When prompted for the first sector, hit Enter. When prompted for the last sector, hit Enter to create a partition that takes up the rest of the remaining space on the disk:
Command (m for help):nPartition type
p primary (2 primary, 0 extended, 2 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (3,4, default 3): 3
First sector (10487808-1953525167, default 10487808):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (10487808-1953525167, default 1953525167):
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<div lang="en" dir="ltr" class="mw-content-ltr">
Created a new partition 3 of type 'Linux' and of size 926.5 GiB.
After completing these steps, pressing p should display a partition table that looks similar to this:
Command (m for help):pDisk /dev/sda: 931.51 GiB, 1000204886016 bytes, 1953525168 sectors Disk model: HGST HTS721010A9 Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disklabel type: dos Disk identifier: 0xf163b576 </div> <div lang="en" dir="ltr" class="mw-content-ltr"> Device Boot Start End Sectors Size Id Type /dev/sda1 * 2048 2099199 2097152 1G 83 Linux /dev/sda2 2099200 10487807 8388608 4G 82 Linux swap / Solaris /dev/sda3 10487808 1953525167 1943037360 926.5G 83 Linux
Saving the partition layout
Press w to write the partition layout and exit fdisk:
Command (m for help):wThe partition table has been altered. Calling ioctl() to re-read partition table. Syncing disks.
Now it is time to put filesystems on the partitions.