Linux 卸载及删除磁盘分区

1.卸载分区

[root@centos7 ~]# df -Th
Filesystem              Type      Size  Used Avail Use% Mounted on
/dev/mapper/centos-root xfs        17G  4.0G   14G  24% /
devtmpfs                devtmpfs  974M     0  974M   0% /dev
tmpfs                   tmpfs     991M     0  991M   0% /dev/shm
tmpfs                   tmpfs     991M   11M  981M   2% /run
tmpfs                   tmpfs     991M     0  991M   0% /sys/fs/cgroup
/dev/sdb1               xfs       8.0G   33M  8.0G   1% /mnt/sdb1
/dev/sdb2               xfs        12G   33M   12G   1% /mnt/sdb2
/dev/sda1               xfs      1014M  166M  849M  17% /boot
tmpfs                   tmpfs     199M  8.0K  199M   1% /run/user/42
tmpfs                   tmpfs     199M     0  199M   0% /run/user/0
[root@centos7 ~]# umount /dev/sdb1
[root@centos7 ~]# umount /dev/sdb2

将fstab文件最后两行关于/dev/sdb1和/dev/sdb2的内容删除

[root@centos7 ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Tue Aug 13 23:27:51 2019
#
# 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=18170546-e5ce-4fd1-9f7a-45df40e45621 /boot                   xfs     defaults        0 0
/dev/mapper/centos-swap swap                    swap    defaults        0 0
/dev/sdb1                            /mnt/sdb1                    xfs     defaults        0 0
/dev/sdb2                            /mnt/sdb2                    xfs     defaults,usrquota,grpquota        0 0

[root@centos7 ~]# vi /etc/fstab
[root@centos7 ~]# cat /etc/fstab

#
# /etc/fstab
# Created by anaconda on Tue Aug 13 23:27:51 2019
#
# 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=18170546-e5ce-4fd1-9f7a-45df40e45621 /boot                   xfs     defaults        0 0
/dev/mapper/centos-swap swap                    swap    defaults        0 0

2.删除分区

[root@centos7 ~]# 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.


Command (m for help): m
Command action
   a   toggle a bootable flag
   b   edit bsd disklabel
   c   toggle the dos compatibility flag
   d   delete a partition
   g   create a new empty GPT partition table
   G   create an IRIX (SGI) partition table
   l   list known partition types
   m   print this menu
   n   add a new partition
   o   create a new empty DOS partition table
   p   print the partition table
   q   quit without saving changes
   s   create a new empty Sun disklabel
   t   change a partition's system id
   u   change display/entry units
   v   verify the partition table
   w   write table to disk and exit
   x   extra functionality (experts only)

Command (m for help): d
Partition number (1,2, default 2):
Partition 2 is deleted

Command (m for help): d
Selected partition 1
Partition 1 is deleted

Command (m for help): p

Disk /dev/sdb: 21.5 GB, 21474836480 bytes, 41943040 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: 0x302fa02d

   Device Boot      Start         End      Blocks   Id  System

Command (m for help): w
The partition table has been altered!

Calling ioctl() to re-read partition table.
Syncing disks.