Linux 磁盘分区
参考:
https://www.cnblogs.com/itech/archive/2010/12/24/1916255.html
https://www.jianshu.com/p/bf939474d69b
gdisk使用参考
https://www.cnblogs.com/Sunzz/p/6908329.html
概念
优于一般linux分配硬盘空间不会超过2T，所以也就无需使用GPT分区表，所以使用MBR分区工具fdisk即可（GPT分区表使用gpart 或是 gdisk）
- 在linux下SCSI接口设备以sd命名，第一个是sda，第二个sdb，依次类推。IDE接口设备用hd命名，第一个是hda，第二个是hdb，依次类推。
- 分区是用设备名称加数字命名。例如sda1代表sda这个硬盘设备上的第一个分区。
- MBR分区、表最多有四个主分区（windows对应C,D,E,F 盘），一个扩展分区，扩张分区可以在分为多个逻辑分区。
我们可以通过 lsblk 命令来查看硬盘，分区以及挂载点
linux 中1-4都是主分区，从5开始为逻辑分区
[root@chz ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 20G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 19G 0 part
├─centos-root 253:0 0 17G 0 lvm /
└─centos-swap 253:1 0 2G 0 lvm [SWAP]
sdb 8:16 0 1G 0 disk
sr0 11:0 1 4.4G 0 rom /run/media/root/CentOS 7 x86_64
[root@chz ~]#
fdisk
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fdisk -l查看所有磁盘和分区
$ sudo fdisk -l Disk /dev/sda: 30 GiB, 32212254720 bytes, 62914560 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: 0xeab59449 Device Boot Start End Sectors Size Id Type /dev/sda1 * 20973568 62914559 41940992 20G 83 Linux Disk /dev/sdb: 10 GiB, 10737418240 bytes, 20971520 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 /dev/sdc: 10 GiB, 10737418240 bytes, 20971520 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 /dev/sdd: 10 GiB, 10737418240 bytes, 20971520 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 /dev/sde: 10 GiB, 10737418240 bytes, 20971520 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这里可以发现，5块硬盘，sda有两个主分区；sda1做为主引导分区。Unites和Sector分别表示扇区大小
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fdisk /dev/sda操作具体某块硬盘
添加磁盘
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在虚拟机中添加一块硬盘
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分区
可以通过 + size {K,M,G} 来指定结束柱面
这里创建了一个100M的主分区sdb1
[root@chz ~]# fdisk /dev/sdb Welcome to fdisk (util-linux 2.23.2). 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 Building a new DOS disklabel with disk identifier 0xac359141. Command (m for help): n Partition type: p primary (0 primary, 0 extended, 4 free) e extended Select (default p): Using default response p #选择主分区 Partition number (1-4, default 1): First sector (2048-2097151, default 2048): Using default value 2048 Last sector, +sectors or +size{K,M,G} (2048-2097151, default 2097151): +100M #结束柱面 Partition 1 of type Linux and of size 100 MiB is set Command (m for help): p Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: dos Disk identifier: 0xac359141 Device Boot Start End Blocks Id System /dev/sdb1 2048 206847 102400 83 Linux Command (m for help): n Partition type: p primary (1 primary, 0 extended, 3 free) #有1个主分区，0个扩展分区，还可以创建3个主分区 e extended Select (default p):创建扩展分区
Command (m for help): n Partition type: p primary (1 primary, 0 extended, 3 free) e extended Select (default p): e #选择扩展分区 Partition number (2-4, default 2): 2 First sector (206848-2097151, default 206848): Using default value 206848 Last sector, +sectors or +size{K,M,G} (206848-2097151, default 2097151): +100M Partition 2 of type Extended and of size 100 MiB is set Command (m for help): p Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: dos Disk identifier: 0xac359141 Device Boot Start End Blocks Id System /dev/sdb1 2048 206847 102400 83 Linux #主分区 /dev/sdb2 206848 411647 102400 5 Extended #扩展分区 Command (m for help):在扩展分区上创建逻辑分区
Command (m for help): n Partition type: p primary (1 primary, 1 extended, 2 free) l logical (numbered from 5) #逻辑分区从5开始计数 Select (default p): l Adding logical partition 5 First sector (208896-411647, default 208896): Using default value 208896 Last sector, +sectors or +size{K,M,G} (208896-411647, default 411647): +20M Partition 5 of type Linux and of size 20 MiB is set Command (m for help): p Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: dos Disk identifier: 0xf9fe9356 Device Boot Start End Blocks Id System /dev/sdb1 2048 206847 102400 83 Linux /dev/sdb2 206848 411647 102400 5 Extended /dev/sdb5 208896 249855 20480 83 Linux Command (m for help):保存分区
Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table.lsblk查看分区[root@chz ~]# lsblk NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT sda 8:0 0 20G 0 disk ├─sda1 8:1 0 1G 0 part /boot └─sda2 8:2 0 19G 0 part ├─centos-root 253:0 0 17G 0 lvm / └─centos-swap 253:1 0 2G 0 lvm [SWAP] sdb 8:16 0 1G 0 disk ├─sdb1 8:17 0 100M 0 part ├─sdb2 8:18 0 1K 0 part └─sdb5 8:21 0 20M 0 part sr0 11:0 1 4.4G 0 rom /run/media/root/CentOS 7 x86_64 -
格式化
这里将 /dev/sdb1分区格式化为ext4文件系统，默认使用ext2
这里mkfs.ext4是mke2fs的衍生命令， 也可以使用mkfs -t ext4 /dev/sdb1
将磁盘挂载后通过 df -T 来查看磁盘的类型
[root@chz ~]# mkfs.ext4 /dev/sdb1 mke2fs 1.42.9 (28-Dec-2013) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 25688 inodes, 102400 blocks 5120 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=33685504 13 block groups 8192 blocks per group, 8192 fragments per group 1976 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729 Allocating group tables: done Writing inode tables: done Creating journal (4096 blocks): done Writing superblocks and filesystem accounting information: done -
挂载
这种方式挂载并不会永久挂载，当重启后失效
[root@chz ~]# mount /dev/sdb1 /root/test [root@chz ~]# df -T Filesystem Type 1K-blocks Used Available Use% Mounted on devtmpfs devtmpfs 480800 0 480800 0% /dev tmpfs tmpfs 497840 0 497840 0% /dev/shm tmpfs tmpfs 497840 8740 489100 2% /run tmpfs tmpfs 497840 0 497840 0% /sys/fs/cgroup /dev/mapper/centos-root xfs 17811456 7798620 10012836 44% / /dev/sda1 xfs 1038336 217148 821188 21% /boot tmpfs tmpfs 99572 20 99552 1% /run/user/0 /dev/sr0 iso9660 4554702 4554702 0 100% /run/media/root/CentOS 7 x86_64 /dev/sdb1 ext4 95054 1550 86336 2% /root/test -
永久挂载
从左至右字段分别为，device or filesystem，mount point，type of filesystem，mount options，which filesystems need to be dumped(0表示不存档)，which filesystems need to be checked(0表示在引导时不需要检查)。
[root@chz ~]# cat /etc/fstab # # /etc/fstab # Created by anaconda on Mon Aug 24 07:49:09 2020 # # Accessible filesystems, by reference, are maintained under '/dev/disk' # See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info # /dev/mapper/centos-root / xfs defaults 0 0 UUID=52ff1027-e9d7-427d-9f43-3a98ba708796 /boot xfs defaults 0 0 /dev/mapper/centos-swap swap swap defaults 0 0 /dev/sdb1 /root/test ext4 defaults 0 0我们也可以通过UUID来挂载，通过
blkid来获取UUID[root@chz ~]# blkid /dev/sda1: UUID="52ff1027-e9d7-427d-9f43-3a98ba708796" TYPE="xfs" /dev/sda2: UUID="eA52jE-SFuU-BG5t-Isyw-wWdY-lj4K-xso1bu" TYPE="LVM2_member" /dev/sdb1: UUID="8492fdac-fc1c-40e7-9548-ba9d3944e348" TYPE="ext4" /dev/sr0: UUID="2019-09-11-18-50-31-00" LABEL="CentOS 7 x86_64" TYPE="iso9660" PTTYPE="dos" /dev/mapper/centos-root: UUID="c18c2095-72b4-49f4-95be-a58d0a6cc2ad" TYPE="xfs" /dev/mapper/centos-swap: UUID="0b4a0dde-4db6-4494-a067-80f3318849f7" TYPE="swap"
删除分区
注意如果直接删除分区，但是没有修改 /etc/fstab中挂载的就会出现give root password for maintenance