Step 1: Unmount and Remove all Filesystems
Table of Contents
Use below commands to remove filesystems
1. umount,
2. lvremove
3. vgremove
Make sure all filesystems have been unmounted and you have access to the all disks.
Remove Logical Volume (LVM)
#lvdisplay /dev/myvg/mylv
#umount /dev/<vgname>/<lvname> (vg name=myvg, lv name=mylv)
#vim /etc/fstab (remove entry from fstab)
#lvremove /dev/myvg/mylv
#vgdisplay /dev/myvg
#vgremove myvg
Step 2: Examine RAID Device
#cat /proc/mdstat
md1 : active raid0 sdc1[1] sdb1[0]
2929555456 blocks super 1.2 [2/2] [UU]
bitmap: 0/22 pages [0KB], 65536KB chunk
md0 : active raid0 sdc1[1] sdb1[0]
976502784 blocks super 1.2 512K chunks 2 near-copies [4/4] [UUUU]
unused devices: &lt;none&gt;
#mdadm –examine /dev/
Example output:
mdadm –examine /dev/sdb1 /dev/sdc1
/dev/sdb1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 96f29f92:bb4a438c:770cb2f6:163de067
Name : localhost.localdomain:raid5 (local to host localhost. localdomain)
Creation Time : Fri Sep 17 11:17:57 2021
Raid Level : raid0
Raid Devices : 2
Avail Dev Size : 2091008 (1021.00 MiB 1070.60 MB)
Array Size : 1045504 (1021.00 MiB 1070.60 MB)
Data Offset : 4096 sectors
Super Offset : 8 sectors
Unused Space : before=4016 sectors, after=0 sectors
State : clean
Device UUID : 65bd1bfc:c0eb6ed5:fe70e6d0:53f75cca
Update Time : Fri Sep 17 11:18:00 2021
Bad Block Log : 512 entries available at offset 16 sectors
Checksum : c9f2f7b2 – correct
Events : 18
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 0
Array State : AA (‘A’ == active, ‘.’ == missing, ‘R’ == replacing)
/dev/sdc1:
Magic : a92b4efc
Version : 1.2
Feature Map : 0x0
Array UUID : 96f29f92:bb4a438c:770cb2f6:163de067
Name : localhost.localdomain:raid5 (local to host localhost. localdomain)
Creation Time : Fri Sep 17 11:17:57 2021
Raid Level : raid0
Raid Devices : 2
Avail Dev Size : 2091008 (1021.00 MiB 1070.60 MB)
Array Size : 1045504 (1021.00 MiB 1070.60 MB)
Data Offset : 4096 sectors
Super Offset : 8 sectors
Unused Space : before=4016 sectors, after=0 sectors
State : clean
Device UUID : 2348fc08:224f6ce8:55aea387:340a2b00
Update Time : Fri Sep 17 11:18:00 2021
Bad Block Log : 512 entries available at offset 16 sectors
Checksum : d65c360a – correct
Events : 18
Layout : left-symmetric
Chunk Size : 512K
Device Role : Active device 1
Array State : AA (‘A’ == active, ‘.’ == missing, ‘R’ == replacing)
Step 3: Stop mdadm RAID device
#mdadm –stop /dev/md0
mdadm: stopped /dev/md/raid5
Step 4: Remove mdadm RAID Device
#mdadm –remove /dev/md0
Some times you receive the error:-
“mdadm: error opening /dev/md0: No such file or directory” you need to remove superblocks
Step 5: Remove the superblocks
#mdadm –zero-superblock /dev/sdb1 /dev/sdc1
#mdadm –remove /dev/md0
Step 6: Verify RAID device was removed
#cat /proc/mdstat
