From 96a36a45bf938f64920bb579be1495552a55039c Mon Sep 17 00:00:00 2001 From: darksun Date: Thu, 31 Jan 2019 10:08:56 +0800 Subject: [PATCH] =?UTF-8?q?=E9=80=89=E9=A2=98:=2020190128=20fdisk=20?= =?UTF-8?q?=E2=80=93=20Easy=20Way=20To=20Manage=20Disk=20Partitions=20In?= =?UTF-8?q?=20Linux=20sources/tech/20190128=20fdisk=20-=20Easy=20Way=20To?= =?UTF-8?q?=20Manage=20Disk=20Partitions=20In=20Linux.md?= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit --- ... Way To Manage Disk Partitions In Linux.md | 524 ++++++++++++++++++ 1 file changed, 524 insertions(+) create mode 100644 sources/tech/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md diff --git a/sources/tech/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md b/sources/tech/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md new file mode 100644 index 0000000000..cc89e8c7f1 --- /dev/null +++ b/sources/tech/20190128 fdisk - Easy Way To Manage Disk Partitions In Linux.md @@ -0,0 +1,524 @@ +[#]: collector: (lujun9972) +[#]: translator: ( ) +[#]: reviewer: ( ) +[#]: publisher: ( ) +[#]: url: ( ) +[#]: subject: (fdisk – Easy Way To Manage Disk Partitions In Linux) +[#]: via: (https://www.2daygeek.com/linux-fdisk-command-to-manage-disk-partitions/) +[#]: author: (Magesh Maruthamuthu https://www.2daygeek.com/author/magesh/) + +fdisk – Easy Way To Manage Disk Partitions In Linux +====== + +Hard disks can be divided into one or more logical disks called partitions. + +This division is described in the partition table (MBR or GPT) found in sector 0 of the disk. + +Linux needs at least one partition, namely for its root file system and we can’t install Linux OS without partitions. + +Once created, a partition must be formatted with an appropriate file system before files can be written to it. + +To do so, we need some utility to perform this in Linux. + +There are many utilities are available for that in Linux. We had written about **[Parted Command][1]** in the past and today we are going to discuss about fdisk. + +fdisk command is one of the the best tool to manage disk partitions in Linux. + +It supports maximum `2 TB`, and everyone prefer to go with fdisk. + +This tool is used by vast of Linux admin because we don’t use more than 2TB now a days due to LVM and SAN. It’s used in most of the infra structure around the world. + +Still if you want to create a large partitions, like more than 2TB then you have to go either **Parted Command** or **cfdisk Command**. + +Disk partition and file system creations is one of the routine task for Linux admin. + +If you are working on vast environment then you have to perform this task multiple times in a day. + +### How Linux Kernel Understand Hard Disks? + +As a human we can easily understand things but computer needs the proper naming conversion to understand each and everything. + +In Linux, devices are located on `/dev` partition and Kernel understand the hard disk in the following format. + + * **`/dev/hdX[a-z]:`** IDE Disk is named hdX in Linux + * **`/dev/sdX[a-z]:`** SCSI Disk is named sdX in Linux + * **`/dev/xdX[a-z]:`** XT Disk is named sdX in Linux + * **`/dev/vdX[a-z]:`** Virtual Hard Disk is named vdX in Linux + * **`/dev/fdN:`** Floppy Drive is named fdN in Linux + * **`/dev/scdN or /dev/srN:`** CD-ROM is named /dev/scdN or /dev/srN in Linux + + + +### What Is fdisk Command? + +fdisk stands for fixed disk or format disk is a cli utility that allow users to perform following actions on disks. It allows us to view, create, resize, delete, move and copy the partitions. + +It understands MBR, Sun, SGI and BSD partition tables and it doesn’t understand GUID Partition Table (GPT) and it is not designed for large partitions. + +fdisk allows us to create a maximum of four primary partitions per disk. One of these may be an extended partition and it holds multiple logical partitions. + +1-4 is reserved for four primary partitions and Logical partitions start numbering from 5. +![][3] + +### How To Install fdisk On Linux + +You don’t need to install fdisk in Linux system because it has installed by default as part of core utility. + +### How To List Available Disks Using fdisk Command + +First we have to know what are the disks were added in the system before performing any action. To list all available disks on your system run the following command. + +It lists possible information about the disks such as disk name, how many partitions are created in it, Disk Size, Disklabel type, Disk Identifier, Partition ID and Partition Type. + +``` +$ sudo fdisk -l +Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 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: 0xeab59449 + +Device Boot Start End Sectors Size Id Type +/dev/sda1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 20973568 62914559 41940992 20G 83 Linux + + +Disk /dev/sdb: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes + + +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes + + +Disk /dev/sdd: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes + + +Disk /dev/sde: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes +I/O size (minimum/optimal): 512 bytes / 512 bytes +``` + +### How To List A Specific Disk Partitions Using fdisk Command + +If you would like to see a specific disk and it’s partitions, use the following format. + +``` +$ sudo fdisk -l /dev/sda +Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 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: 0xeab59449 + +Device Boot Start End Sectors Size Id Type +/dev/sda1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 20973568 62914559 41940992 20G 83 Linux +``` + +### How To List Available Actions For fdisk Command + +When you hit `m` in the fdisk command that will show you available actions for fdisk command. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + +Device does not contain a recognized partition table. +Created a new DOS disklabel with disk identifier 0xe944b373. + +Command (m for help): m + +Help: + + DOS (MBR) + a toggle a bootable flag + b edit nested BSD disklabel + c toggle the dos compatibility flag + + Generic + d delete a partition + F list free unpartitioned space + l list known partition types + n add a new partition + p print the partition table + t change a partition type + v verify the partition table + i print information about a partition + + Misc + m print this menu + u change display/entry units + x extra functionality (experts only) + + Script + I load disk layout from sfdisk script file + O dump disk layout to sfdisk script file + + Save & Exit + w write table to disk and exit + q quit without saving changes + + Create a new label + g create a new empty GPT partition table + G create a new empty SGI (IRIX) partition table + o create a new empty DOS partition table + s create a new empty Sun partition table +``` + +### How To List Partitions Types Using fdisk Command + +When you hit `l` in the fdisk command that will show you an available partitions type for fdisk command. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + +Device does not contain a recognized partition table. +Created a new DOS disklabel with disk identifier 0x9ffd00db. + +Command (m for help): l + + 0 Empty 24 NEC DOS 81 Minix / old Lin bf Solaris + 1 FAT12 27 Hidden NTFS Win 82 Linux swap / So c1 DRDOS/sec (FAT- + 2 XENIX root 39 Plan 9 83 Linux c4 DRDOS/sec (FAT- + 3 XENIX usr 3c PartitionMagic 84 OS/2 hidden or c6 DRDOS/sec (FAT- + 4 FAT16 <32M 40 Venix 80286 85 Linux extended c7 Syrinx + 5 Extended 41 PPC PReP Boot 86 NTFS volume set da Non-FS data + 6 FAT16 42 SFS 87 NTFS volume set db CP/M / CTOS / . + 7 HPFS/NTFS/exFAT 4d QNX4.x 88 Linux plaintext de Dell Utility + 8 AIX 4e QNX4.x 2nd part 8e Linux LVM df BootIt + 9 AIX bootable 4f QNX4.x 3rd part 93 Amoeba e1 DOS access + a OS/2 Boot Manag 50 OnTrack DM 94 Amoeba BBT e3 DOS R/O + b W95 FAT32 51 OnTrack DM6 Aux 9f BSD/OS e4 SpeedStor + c W95 FAT32 (LBA) 52 CP/M a0 IBM Thinkpad hi ea Rufus alignment + e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a5 FreeBSD eb BeOS fs + f W95 Ext'd (LBA) 54 OnTrackDM6 a6 OpenBSD ee GPT +10 OPUS 55 EZ-Drive a7 NeXTSTEP ef EFI (FAT-12/16/ +11 Hidden FAT12 56 Golden Bow a8 Darwin UFS f0 Linux/PA-RISC b +12 Compaq diagnost 5c Priam Edisk a9 NetBSD f1 SpeedStor +14 Hidden FAT16 <3 61 SpeedStor ab Darwin boot f4 SpeedStor +16 Hidden FAT16 63 GNU HURD or Sys af HFS / HFS+ f2 DOS secondary +17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fb VMware VMFS +18 AST SmartSleep 65 Novell Netware b8 BSDI swap fc VMware VMKCORE +1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fd Linux raid auto +1c Hidden W95 FAT3 75 PC/IX bc Acronis FAT32 L fe LANstep +1e Hidden W95 FAT1 80 Old Minix be Solaris boot ff BBT +``` + +### How To Create A Disk Partition Using fdisk Command + +If you would like to create a new partition use the following steps. In my case, i'm going to create 4 partitions (3 Primary and 1 Extended) on `/dev/sdc` disk. To the same for other partitions too. + +As this takes value from partition table so, hit `Enter` for first sector. Enter the size which you want to set for the partition (We can add a partition size using KB,MB,G and TB) for last sector. + +For example, if you would like to add 1GB partition then the last sector value should be `+1G`. Once you have created 3 partitions, it will automatically change the partition type to extended as a default. If you still want to create a fourth primary partitions then hit `p` instead of default value `e`. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): n +Partition type + p primary (0 primary, 0 extended, 4 free) + e extended (container for logical partitions) +Select (default p): Enter + +Using default response p. +Partition number (1-4, default 1): Enter +First sector (2048-20971519, default 2048): Enter +Last sector, +sectors or +size{K,M,G,T,P} (2048-20971519, default 20971519): +1G + +Created a new partition 1 of type 'Linux' and of size 1 GiB. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 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: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### How To Create A Extended Disk Partition Using fdisk Command + +Make a note, you have to use remaining all space when you create a extended partition because again you can able to create multiple logical partition in that. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): n +Partition type + p primary (3 primary, 0 extended, 1 free) + e extended (container for logical partitions) +Select (default e): Enter + +Using default response e. +Selected partition 4 +First sector (6293504-20971519, default 6293504): Enter +Last sector, +sectors or +size{K,M,G,T,P} (6293504-20971519, default 20971519): Enter + +Created a new partition 4 of type 'Extended' and of size 7 GiB. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 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: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux +/dev/sdc2 2099200 4196351 2097152 1G 83 Linux +/dev/sdc3 4196352 6293503 2097152 1G 83 Linux +/dev/sdc4 6293504 20971519 14678016 7G 5 Extended + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### How To View Unpartitioned Disk Space Using fdisk Command + +As described in the above section, we have totally created 4 partitions (3 Primary and 1 Extended). Extended partition disk space will show unpartitioned until you create a logical partitions in that. + +Use the following command to view the unpartitioned space for a disk. As per the below output we have `7GB` unpartitioned disk. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): F +Unpartitioned space /dev/sdc: 7 GiB, 7515144192 bytes, 14678016 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 512 = 512 bytes +Sector size (logical/physical): 512 bytes / 512 bytes + + Start End Sectors Size +6293504 20971519 14678016 7G + +Command (m for help): q +``` + +### How To Create A Logical Partition Using fdisk Command + +Follow the same above procedure to create a logical partition once you have created the extended partition. +Here, i have created `1GB` of logical partition called `/dev/sdc5`, you can double confirm this by checking the partition table value. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + +Command (m for help): n +All primary partitions are in use. +Adding logical partition 5 +First sector (6295552-20971519, default 6295552): Enter +Last sector, +sectors or +size{K,M,G,T,P} (6295552-20971519, default 20971519): +1G + +Created a new partition 5 of type 'Linux' and of size 1 GiB. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 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: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux +/dev/sdc2 2099200 4196351 2097152 1G 83 Linux +/dev/sdc3 4196352 6293503 2097152 1G 83 Linux +/dev/sdc4 6293504 20971519 14678016 7G 5 Extended +/dev/sdc5 6295552 8392703 2097152 1G 83 Linux + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### How To Delete A Partition Using fdisk Command + +If the partition is no more used in the system than we can remove it by using the below steps. + +Make sure you have to enter the correct partition number to delete it. In this case, i'm going to remove `/dev/sdc2` partition. + +``` +$ sudo fdisk /dev/sdc + +Welcome to fdisk (util-linux 2.30.1). +Changes will remain in memory only, until you decide to write them. +Be careful before using the write command. + + +Command (m for help): d +Partition number (1-5, default 5): 2 + +Partition 2 has been deleted. + +Command (m for help): p +Disk /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 sectors +Units: sectors of 1 core.md Dict.md lctt2014.md lctt2016.md lctt2018.md LICENSE published README.md scripts sources translated 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: 0x8cc8f9e5 + +Device Boot Start End Sectors Size Id Type +/dev/sdc1 2048 2099199 2097152 1G 83 Linux +/dev/sdc3 4196352 6293503 2097152 1G 83 Linux +/dev/sdc4 6293504 20971519 14678016 7G 5 Extended +/dev/sdc5 6295552 8392703 2097152 1G 83 Linux + +Command (m for help): w +The partition table has been altered. +Calling ioctl() to re-read partition table. +Syncing disks. +``` + +### How To Format A Partition Or Create A FileSystem On The Partition + +In computing, a file system or filesystem controls how data is stored and retrieved through inode tables. + +Without a file system, the system can't find where the information is stored on the partition. Filesystem can be created in three ways. Here, i'm going to create a filesystem on `/dev/sdc1` partition. + +``` +$ sudo mkfs.ext4 /dev/sdc1 +or +$ sudo mkfs -t ext4 /dev/sdc1 +or +$ sudo mke2fs /dev/sdc1 + +mke2fs 1.43.5 (04-Aug-2017) +Creating filesystem with 262144 4k blocks and 65536 inodes +Filesystem UUID: c0a99b51-2b61-4f6a-b960-eb60915faab0 +Superblock backups stored on blocks: + 32768, 98304, 163840, 229376 + +Allocating group tables: done +Writing inode tables: done +Creating journal (8192 blocks): done +Writing superblocks and filesystem accounting information: done +``` + +When you creating a filesystem on tha partition that will create the following important things on it. + + * **`Filesystem UUID:`** UUID stands for Universally Unique Identifier, UUIDs are used to identify block devices in Linux. It's 128 bit long numbers represented by 32 hexadecimal digits. + * **`Superblock:`** Superblock stores metadata of the file system. If the superblock of a file system is corrupted, then the filesystem cannot be mounted and thus files cannot be accessed. + * **`Inode:`** An inode is a data structure on a filesystem on a Unix-like operating system that stores all the information about a file except its name and its actual data. + * **`Journal:`** A journaling filesystem is a filesystem that maintains a special file called a journal that is used to repair any inconsistencies that occur as the result of an improper shutdown of a computer. + + + +### How To Mount A Partition In Linux + +Once you have created the partition and filesystem then we need to mount the partition to use. + +To do so, we need to create a mountpoint to mount the partition. Use mkdir command to create a mountpoint. + +``` +$ sudo mkdir -p /mnt/2g-new +``` + +For temporary mount, use the following command. You will be lose this mountpoint after rebooting your system. + +``` +$ sudo mount /dev/sdc1 /mnt/2g-new +``` + +For permanent mount, add the partition details in the fstab file. It can be done in two ways either adding device name or UUID value. + +Permanent mount using Device Name: + +``` +# vi /etc/fstab + +/dev/sdc1 /mnt/2g-new ext4 defaults 0 0 +``` + +Permanent mount using UUID Value. To get a UUID of the partition use blkid command. + +``` +$ sudo blkid +/dev/sdc1: UUID="d17e3c31-e2c9-4f11-809c-94a549bc43b7" TYPE="ext2" PARTUUID="8cc8f9e5-01" +/dev/sda1: UUID="d92fa769-e00f-4fd7-b6ed-ecf7224af7fa" TYPE="ext4" PARTUUID="eab59449-01" +/dev/sdc3: UUID="ca307aa4-0866-49b1-8184-004025789e63" TYPE="ext4" PARTUUID="8cc8f9e5-03" +/dev/sdc5: PARTUUID="8cc8f9e5-05" + +# vi /etc/fstab + +UUID=d17e3c31-e2c9-4f11-809c-94a549bc43b7 /mnt/2g-new ext4 defaults 0 0 +``` + +The same has been verified using df Command. + +``` +$ df -h +Filesystem Size Used Avail Use% Mounted on +udev 969M 0 969M 0% /dev +tmpfs 200M 7.0M 193M 4% /run +/dev/sda1 20G 16G 3.0G 85% / +tmpfs 997M 0 997M 0% /dev/shm +tmpfs 5.0M 4.0K 5.0M 1% /run/lock +tmpfs 997M 0 997M 0% /sys/fs/cgroup +tmpfs 200M 28K 200M 1% /run/user/121 +tmpfs 200M 25M 176M 13% /run/user/1000 +/dev/sdc1 1008M 1.3M 956M 1% /mnt/2g-new +``` + +-------------------------------------------------------------------------------- + +via: https://www.2daygeek.com/linux-fdisk-command-to-manage-disk-partitions/ + +作者：[Magesh Maruthamuthu][a] +选题：[lujun9972][b] +译者：[译者ID](https://github.com/译者ID) +校对：[校对者ID](https://github.com/校对者ID) + +本文由 [LCTT](https://github.com/LCTT/TranslateProject) 原创编译，[Linux中国](https://linux.cn/) 荣誉推出 + +[a]: https://www.2daygeek.com/author/magesh/ +[b]: https://github.com/lujun9972 +[1]: https://www.2daygeek.com/how-to-manage-disk-partitions-using-parted-command/ +[2]: data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7 +[3]: https://www.2daygeek.com/wp-content/uploads/2019/01/linux-fdisk-command-to-manage-disk-partitions-1a.png