一.1.
系统中添加一块硬盘，虚拟机处于关闭状态
2.如何识别系统中的设备
/dev/vdb:
v表示虚拟，virtual
[root@server8 ~]# df
df查看挂载情况
[root@server8 ~]# df -h 2的n次方
[root@server8 ~]# df -H 10的n次方
显示单位，h和H计算方式不同
[root@server8 ~]# lsblk
查看设备使用情况
[root@server8 ~]# blkid
/dev/vda1: UUID="658e2a5d-acb6-45e5-ba91-a974e37a6c68" TYPE="xfs" PARTUUID="6c106e59-01"
/dev/vda2: UUID="4ZojnM-GEf8-cYun-5Kf8-ZPbV-dtrY-nLEth0" TYPE="LVM2_member" PARTUUID="6c106e59-02"
/dev/mapper/rhel-root: UUID="77027b45-bfe1-48fe-9d6b-840c2b506266" TYPE="xfs"
/dev/mapper/rhel-swap: UUID="a0e0133b-52a3-4773-8d5f-e1c140b30408" TYPE="swap"
查看系统设备的ID
[root@server8 ~]# cat /proc/partitions
major minor #blocks name
252 0 15728640 vda
252 1 1048576 vda1
252 2 14679040 vda2
252 16 5242880 vdb
253 0 13103104 dm-0
253 1 1572864 dm-1
查看系统识别设备
[root@server8 ~]# fdisk -l
Disk /dev/vda: 15 GiB, 16106127360 bytes, 31457280 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: 0x6c106e59
Device Boot Start End Sectors Size Id Type
/dev/vda1 * 2048 2099199 2097152 1G 83 Linux
/dev/vda2 2099200 31457279 29358080 14G 8e Linux LVM
Disk /dev/vdb: 5 GiB, 5368709120 bytes, 10485760 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/mapper/rhel-root: 12.5 GiB, 13417578496 bytes, 26206208 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/mapper/rhel-swap: 1.5 GiB, 1610612736 bytes, 3145728 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
查看真实的设备情况用此命令
3.设备的挂载
umount
mount
卸载和挂载
当处于挂载点时，不可以卸载，因为设备正忙
[root@server8 ~]# fuser -vm /mnt/
查看设备上运行的程序
[root@server8 ~]# fuser -kvm /mnt/
此命令可以结束设备上绝大多数程序
[root@server8 ~]# mount -o ro /dev/vda1 /mnt/
只读挂载
直接在shell中输入mount就可以看到所有的挂载信息
[root@server8 ~]# mount -o remount,rw /mnt
重新挂载mnt目录的设备并可以读写
4.磁盘分区
MBR
主分区和扩展分区，扩展分区包含逻辑分区
GPT，有一个efi分区，剩下的都是efi管理的分区，没有主分区，所有分区都可以是主分区
[root@server8 ~]# fdisk /dev/vdb
进入磁盘按m
默认是DOS
也可以调整成GPT类型
n新建，p主分区，e拓展分区
当出现四个主分区时，即使磁盘还有容量也要将一个主分区调整成为子分区
删除分区用d
会提示删除第几个分区
GPT分区：
Command (m for help): g
Created a new GPT disklabel (GUID: 6E35D32B-9265-DA4B-BCF9-6EBEA47F45EE).
Command (m for help): p
Disk /dev/vdb: 5 GiB, 5368709120 bytes, 10485760 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: gpt
Disk identifier: 6E35D32B-9265-DA4B-BCF9-6EBEA47F45EE
Command (m for help): n
Partition number (2-128, default 2):
First sector (206848-10485726, default 206848):
Last sector, +sectors or +size{K,M,G,T,P} (206848-10485726, default 10485726): +100M
Created a new partition 2 of type 'Linux filesystem' and of size 100 MiB.
Command (m for help): p
Disk /dev/vdb: 5 GiB, 5368709120 bytes, 10485760 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: gpt
Disk identifier: 6E35D32B-9265-DA4B-BCF9-6EBEA47F45EE
Device Start End Sectors Size Type
/dev/vdb1 2048 206847 204800 100M Linux filesystem
/dev/vdb2 206848 411647 204800 100M Linux filesystem
[root@server8 ~]# udevadm settle
同步分区表到系统可以看到划分的分区已经产生，如果不想要了怎么做？
[root@server8 ~]# fdisk /dev/vdb
Welcome to fdisk (util-linux 2.32.1).
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 (1,2, default 2): 1
Partition 1 has been deleted.
Command (m for help): d
Selected partition 2
Partition 2 has been deleted.
当删除设备时一定确保设备在系统中未被使用
[root@server8 ~]# dd if=/dev/zero of=/dev/vdb bs=1M count=1
1+0 records in
1+0 records out
1048576 bytes (1.0 MB, 1.0 MiB) copied, 0.00212607 s, 493 MB/s
完整的清理分区
如何用命令建立分区？
[root@server8 ~]# parted /dev/vdb mklabel msdos
Information: You may need to update /etc/fstab.
命令建立一个dos分区
[root@server8 ~]# parted /dev/vdb mklabel gpt
Warning: The existing disk label on /dev/vdb will be destroyed and all data on
this disk will be lost. Do you want to continue?
Yes/No? yes
Information: You may need to update /etc/fstab.
[root@server8 ~]# parted /dev/vdb mkpart primary 1 100
[root@server8 ~]# parted /dev/vdb mkpart primary 101 200
开始划分分区的方式就是这样，后一个不能根前一个数字重合
，下一个就是201-300
删除怎么删除？
[root@server8 ~]# parted /dev/vdb rm 2
Information: You may need to update /etc/fstab.
[root@server8 ~]# parted /dev/vdb rm 1
Information: You may need to update /etc/fstab.
删除分区
这是非交互式使用命令来删除分区
5.格式化设备并且自动挂载及fstab文件处理
新设备不能挂载，需要格式化
[root@server8 ~]# mount /dev/vdb1 /mnt/
mount: /mnt: wrong fs type, bad option, bad superblock on /dev/vdb1, missing codepage or helper program, or other error.
如何格式化？
[root@server8 ~]# mkfs.xfs /dev/vdb1
meta-data=/dev/vdb1 isize=512 agcount=4, agsize=6400 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=1, sparse=1, rmapbt=0
= reflink=1
data = bsize=4096 blocks=25600, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0, ftype=1
log =internal log bsize=4096 blocks=1368, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
如果原本设备有数据，在最后加参数-f强制格式化
[root@server8 ~]# mount /dev/vdb1 /mnt/
[root@server8 ~]# df
Filesystem 1K-blocks Used Available Use% Mounted on
devtmpfs 906112 0 906112 0% /dev
tmpfs 935136 0 935136 0% /dev/shm
tmpfs 935136 17612 917524 2% /run
tmpfs 935136 0 935136 0% /sys/fs/cgroup
/dev/mapper/rhel-root 13092864 4825336 8267528 37% /
/dev/vda1 1038336 233980 804356 23% /boot
tmpfs 187024 1180 185844 1% /run/user/42
tmpfs 187024 4 187020 1% /run/user/0
/dev/vdb1 96928 6068 90860 7% /mnt
/dev/vdb1: UUID="2a86168c-345d-412f-984b-5333dcd3c2b2" TYPE="xfs" PARTUUID="fd00c604-01"
此时设备id也有了
这是临时挂载，当重启系统以后就没有了，如何永久挂载？
[root@server8 ~]# vim /etc/fstab
设备 挂载点 文件系统类型 挂载参数 是否备份 是否检测
[root@server8 ~]# mount -a
让刚才执行的生效
重启测试一下，df
/dev/vdb1 96928 6068 90860 7% /mnt
开机自动挂载了
如果不理解各个参数，输入man 5 fstab
当文件内容书写有问题，会导致系统启动失败，一定要注意