今天在服务器创建lvm时，遇到如下报错：
[root@localhost ~]# pvcreate /dev/sdb /dev/sdc /dev/sdd
Cannot use /dev/sdb: device is an md component
Cannot use /dev/sdc: device is an md component
Cannot use /dev/sdd: device is an md component
经过排查发现这台服务器之前做过软raid，配置并未全部清理
[root@localhost ~]# lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT
NAME SIZE FSTYPE TYPE MOUNTPOINT
sda 16G disk
├─sda1 2G xfs part /boot
└─sda2 14G LVM2_member part
└─vg--work-root 14G ext4 lvm /
sdb 16G linux_raid_member disk
sdc 16G linux_raid_member disk
sdd 16G linux_raid_member disk
sr0 1024M rom
目前已确认raid设备已经手动停止
#经沟通之前已执行过如下命令
[root@localhost ~]# mdadm --stop /dev/md0
mdadm: stopped /dev/md0
现只需要将磁盘上的阵列信息清理掉
[root@localhost ~]# mdadm --zero-superblock /dev/sdb
[root@localhost ~]# mdadm --zero-superblock /dev/sdc
[root@localhost ~]# mdadm --zero-superblock /dev/sdd
现在再执行lsblk命令发现磁盘类型已经不为“linux_raid_member”
[root@localhost ~]# lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT
NAME SIZE FSTYPE TYPE MOUNTPOINT
sda 16G disk
├─sda1 2G xfs part /boot
└─sda2 14G LVM2_member part
└─vg--work-root 14G ext4 lvm /
sdb 16G disk
sdc 16G disk
sdd 16G disk
sr0 1024M rom
然后就可以正常创建PV了
[root@localhost ~]# pvcreate /dev/sdb /dev/sdc /dev/sdd
Physical volume "/dev/sdb" successfully created.
Physical volume "/dev/sdc" successfully created.
Physical volume "/dev/sdd" successfully created.
软raid的创建方式也很简单，首先需要安装mdadm工具
[root@localhost ~]# yum -y install mdadm
Last metadata expiration check: 3:11:06 ago on Tue 19 Aug 2025 04:19:36 AM EDT.
Dependencies resolved.
====================================================================================================================================================================================================
Package Architecture Version Repository Size
====================================================================================================================================================================================================
Installing:
mdadm x86_64 4.3-4.el9_5 BaseOS 435 k
Transaction Summary
====================================================================================================================================================================================================
Install 1 Package
Total download size: 435 k
Installed size: 1.0 M
Downloading Packages:
mdadm-4.3-4.el9_5.x86_64.rpm 12 MB/s | 435 kB 00:00
----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Total 11 MB/s | 435 kB 00:00
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
Preparing : 1/1
Installing : mdadm-4.3-4.el9_5.x86_64 1/1
Running scriptlet: mdadm-4.3-4.el9_5.x86_64 1/1
Created symlink /etc/systemd/system/multi-user.target.wants/mdmonitor.service → /usr/lib/systemd/system/mdmonitor.service.
Verifying : mdadm-4.3-4.el9_5.x86_64 1/1
Installed:
mdadm-4.3-4.el9_5.x86_64
Complete!
手动创建软raid
[root@localhost ~]# mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb /dev/sdc /dev/sdd
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.
其中：
- /dev/md0是软raid的名字
- --level=5是raid级别
格式化软raid
[root@localhost ~]# mkfs.ext4 /dev/md0
mke2fs 1.46.5 (30-Dec-2021)
/dev/md0 contains a ext4 file system
last mounted on Tue Aug 19 02:15:42 2025
然后就可以挂载使用了
[root@localhost ~]# mount /dev/md0 /mnt
[root@localhost ~]# lsblk -o NAME,SIZE,FSTYPE,TYPE,MOUNTPOINT
NAME SIZE FSTYPE TYPE MOUNTPOINT
sda 16G disk
├─sda1 2G xfs part /boot
└─sda2 14G LVM2_member part
└─vg--work-root 14G ext4 lvm /
sdb 16G linux_raid_member disk
└─md0 32G ext4 raid5 /mnt
sdc 16G linux_raid_member disk
└─md0 32G ext4 raid5 /mnt
sdd 16G linux_raid_member disk
└─md0 32G ext4 raid5 /mnt
sr0 1024M rom