How to configure RAID 1 on Rocky Linux 8.6

To Configure RAID 1 On Rocky Linux 8.6

Introduction:

RAID 1 is composed of an exact copy (or mirror) of a set of data on two or more disks; a classic RAID 1 mirrored pair has two disks. When using a RAID 1 volume, information is written to a first drive and to a second (or "mirror") drive simultaneously. It is not necessary to remove any information from the remaining hard drive if one of the drives in the mirror volume fails.

Advantage:

RAID 1 has the advantage of providing improved read speeds and additional protection of the hard disks.

Disadvantage:

Uses only half of the storage capacity. More expensive (needs twice as many drivers). Requires powering down your computer to replace failed drive.

Installation Steps:

Step 1: Check the Oracle Linux version by using the below command

[root@linuxhelp ~]# cat /etc/os-release 
NAME="Rocky Linux"
VERSION="8.6 (Green Obsidian)"
ID="rocky"
ID_LIKE="rhel centos fedora"
VERSION_ID="8.6"
PLATFORM_ID="platform:el8"
PRETTY_NAME="Rocky Linux 8.6 (Green Obsidian)"
ANSI_COLOR="0;32"
CPE_NAME="cpe:/o:rocky:rocky:8:GA"
HOME_URL="https://rockylinux.org/"
BUG_REPORT_URL="https://bugs.rockylinux.org/"
ROCKY_SUPPORT_PRODUCT="Rocky Linux"
ROCKY_SUPPORT_PRODUCT_VERSION="8"
REDHAT_SUPPORT_PRODUCT="Rocky Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="8"

Step 2: Install the mdadm package which is a RAID managing tool by using the below command

[root@linuxhelp ~]# yum install mdadm
Last metadata expiration check: 0:04:40 ago on Fri 09 Sep 2022 03:44:26 PM EDT.
Dependencies resolved.
=================================================================================================
 Package              Architecture          Version                  Repository             Size
=================================================================================================


Installing:
 mdadm                x86_64                4.2-2.el8                baseos                459 k

Transaction Summary
=================================================================================================
Install  1 Package

Total download size: 459 k
Installed size: 1.1 M
Is this ok [y/N]: y
Downloading Packages:
mdadm-4.2-2.el8.x86_64.rpm                                       1.4 MB/s | 459 kB     00:00    
-------------------------------------------------------------------------------------------------
Total                                                            427 kB/s | 459 kB     00:01     
Rocky Linux 8 - BaseOS                                           1.4 MB/s | 1.6 kB     00:00    
Importing GPG key 0x6D745A60:
 Userid     : "Release Engineering <infrastructure@rockylinux.org>"
 Fingerprint: 7051 C470 A929 F454 CEBE 37B7 15AF 5DAC 6D74 5A60
 From       : /etc/pki/rpm-gpg/RPM-GPG-KEY-rockyofficial
Is this ok [y/N]: y
Key imported successfully
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                                         1/1 
  Installing       : mdadm-4.2-2.el8.x86_64                                                  1/1 
  Running scriptlet: mdadm-4.2-2.el8.x86_64                                                  1/1 
  Verifying        : mdadm-4.2-2.el8.x86_64                                                  1/1 
Installed:
  mdadm-4.2-2.el8.x86_64                                                                         
Complete!

Step 3: Check if the device is available to configure RAID by using the below command

[root@linuxhelp ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE MOUNTPOINT
sda           8:0    0   35G  0 disk 
├─sda1        8:1    0    1G  0 part /boot
└─sda2        8:2    0   34G  0 part 
  ├─rl-root 253:0    0   31G  0 lvm  /
  └─rl-swap 253:1    0    3G  0 lvm  [SWAP]
sdb           8:16   0    5G  0 disk 
sdc           8:32   0    5G  0 disk 
sr0          11:0    1 1024M  0 rom  

Step 4: Create the partition for two disks by using the below command

[root@linuxhelp ~]# fdisk /dev/sdb
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.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0xe7a8668b.
Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): 
Using default response p.
Partition number (1-4, default 1): 
First sector (2048-10485759, default 2048): 
Last sector, +sectors or +size{K,M,G,T,P} (2048-10485759, default 10485759): 
Created a new partition 1 of type 'Linux' and of size 5 GiB.
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): l
 0  Empty           24  NEC DOS         81  Minix / old Lin bf  Solaris        
 1  FAT12           27  Hidden NTFS Win 82  Linux swap / So c1  DRDOS/sec (FAT-
 2  XENIX root      39  Plan 9          83  Linux           c4  DRDOS/sec (FAT-
 3  XENIX usr       3c  PartitionMagic  84  OS/2 hidden or  c6  DRDOS/sec (FAT-
 4  FAT16 <32M      40  Venix 80286     85  Linux extended  c7  Syrinx         
 5  Extended        41  PPC PReP Boot   86  NTFS volume set da  Non-FS data    
 6  FAT16           42  SFS             87  NTFS volume set db  CP/M / CTOS / .
 7  HPFS/NTFS/exFAT 4d  QNX4.x          88  Linux plaintext de  Dell Utility   
 8  AIX             4e  QNX4.x 2nd part 8e  Linux LVM       df  BootIt         
 9  AIX bootable    4f  QNX4.x 3rd part 93  Amoeba          e1  DOS access     
 a  OS/2 Boot Manag 50  OnTrack DM      94  Amoeba BBT      e3  DOS R/O        
 b  W95 FAT32       51  OnTrack DM6 Aux 9f  BSD/OS          e4  SpeedStor      
 c  W95 FAT32 (LBA) 52  CP/M            a0  IBM Thinkpad hi ea  Rufus alignment
 e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a5  FreeBSD         eb  BeOS fs        
 f  W95 Ext'd (LBA) 54  OnTrackDM6      a6  OpenBSD         ee  GPT            
10  OPUS            55  EZ-Drive        a7  NeXTSTEP        ef  EFI (FAT-12/16/
11  Hidden FAT12    56  Golden Bow      a8  Darwin UFS      f0  Linux/PA-RISC b
12  Compaq diagnost 5c  Priam Edisk     a9  NetBSD          f1  SpeedStor      
14  Hidden FAT16 <3 61  SpeedStor       ab  Darwin boot     f4  SpeedStor      
16  Hidden FAT16    63  GNU HURD or Sys af  HFS / HFS+      f2  DOS secondary  
17  Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fb  VMware VMFS    
18  AST SmartSleep  65  Novell Netware  b8  BSDI swap       fc  VMware VMKCORE 
1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid fd  Linux raid auto
1c  Hidden W95 FAT3 75  PC/IX           bc  Acronis FAT32 L fe  LANstep        
1e  Hidden W95 FAT1 80  Old Minix       be  Solaris boot    ff  BBT            
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linux raid autodetect'.

Command (m for help): p
Disk /dev/sdb: 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: dos
Disk identifier: 0xe7a8668b
Device     Boot Start      End  Sectors Size Id Type
/dev/sdb1        2048 10485759 10483712   5G fd Linux raid autodetect
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

[root@linuxhelp ~]# fdisk /dev/sdc
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.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x249d77e5.
Command (m for help): n
Partition type
   p   primary (0 primary, 0 extended, 4 free)
   e   extended (container for logical partitions)
Select (default p): 
Using default response p.
Partition number (1-4, default 1): 
First sector (2048-10485759, default 2048): 
Last sector, +sectors or +size{K,M,G,T,P} (2048-10485759, default 10485759): 
Created a new partition 1 of type 'Linux' and of size 5 GiB.
Command (m for help): t
Selected partition 1
Hex code (type L to list all codes): l
 0  Empty           24  NEC DOS         81  Minix / old Lin bf  Solaris        
 1  FAT12           27  Hidden NTFS Win 82  Linux swap / So c1  DRDOS/sec (FAT-
 2  XENIX root      39  Plan 9          83  Linux           c4  DRDOS/sec (FAT-
 3  XENIX usr       3c  PartitionMagic  84  OS/2 hidden or  c6  DRDOS/sec (FAT-
 4  FAT16 <32M      40  Venix 80286     85  Linux extended  c7  Syrinx      
 5  Extended        41  PPC PReP Boot   86  NTFS volume set da  Non-FS data    
 6  FAT16           42  SFS             87  NTFS volume set db  CP/M / CTOS / .
 7  HPFS/NTFS/exFAT 4d  QNX4.x          88  Linux plaintext de  Dell Utility   
 8  AIX             4e  QNX4.x 2nd part 8e  Linux LVM       df  BootIt         
 9  AIX bootable    4f  QNX4.x 3rd part 93  Amoeba          e1  DOS access     
 a  OS/2 Boot Manag 50  OnTrack DM      94  Amoeba BBT      e3  DOS R/O        
 b  W95 FAT32       51  OnTrack DM6 Aux 9f  BSD/OS          e4  SpeedStor      
 c  W95 FAT32 (LBA) 52  CP/M            a0  IBM Thinkpad hi ea  Rufus alignment
 e  W95 FAT16 (LBA) 53  OnTrack DM6 Aux a5  FreeBSD         eb  BeOS fs        
 f  W95 Ext'd (LBA) 54  OnTrackDM6      a6  OpenBSD         ee  GPT            
10  OPUS            55  EZ-Drive        a7  NeXTSTEP        ef  EFI (FAT-12/16/
11  Hidden FAT12    56  Golden Bow      a8  Darwin UFS      f0  Linux/PA-RISC b
12  Compaq diagnost 5c  Priam Edisk     a9  NetBSD          f1  SpeedStor      
14  Hidden FAT16 <3 61  SpeedStor       ab  Darwin boot     f4  SpeedStor      
16  Hidden FAT16    63  GNU HURD or Sys af  HFS / HFS+      f2  DOS secondary  
17  Hidden HPFS/NTF 64  Novell Netware  b7  BSDI fs         fb  VMware VMFS    
18  AST SmartSleep  65  Novell Netware  b8  BSDI swap       fc  VMware VMKCORE 
1b  Hidden W95 FAT3 70  DiskSecure Mult bb  Boot Wizard hid fd  Linux raid auto
1c  Hidden W95 FAT3 75  PC/IX           bc  Acronis FAT32 L fe  LANstep        
1e  Hidden W95 FAT1 80  Old Minix       be  Solaris boot    ff  BBT            
Hex code (type L to list all codes): fd
Changed type of partition 'Linux' to 'Linux raid autodetect'.

Command (m for help): p
Disk /dev/sdc: 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: dos
Disk identifier: 0x249d77e5
Device     Boot Start      End  Sectors Size Id Type
/dev/sdc1        2048 10485759 10483712   5G fd Linux raid autodetect
Command (m for help): w
The partition table has been altered.
Calling ioctl() to re-read partition table.
Syncing disks.

Step 5: Next check the block details for any previous configuration that has been made in the disk by using the below command

[root@linuxhelp ~]# mdadm -E /dev/sd[b-c]1
mdadm: No md superblock detected on /dev/sdb1.
mdadm: No md superblock detected on /dev/sdc1.

Step 6: Create the md device and select the RAID levels by using the below command

[root@linuxhelp ~]# mdadm --create /dev/md1 --level=1 --raid-devices=2 /dev/sd[b-c]1
mdadm: Note: this array has metadata at the start and
    may not be suitable as a boot device.  If you plan to
    store '/boot' on this device please ensure that
    your boot-loader understands md/v1.x metadata, or use
    --metadata=0.90
Continue creating array? 
Continue creating array? (y/n) y
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md1 started.

Step 7: Verify the status of RAID level by using the below command

[root@linuxhelp ~]# mdadm -E /dev/sd[b-c]1
/dev/sdb1:
          Magic : a92b4efc
        Version : 1.2
    Feature Map : 0x0
     Array UUID : ea4a83e1:dcc2457f:cdc92d4e:be46b105
           Name : linuxhelp:1  (local to host linuxhelp)
  Creation Time : Fri Sep  9 16:08:34 2022
     Raid Level : raid1
   Raid Devices : 2
 Avail Dev Size : 10473472 sectors (4.99 GiB 5.36 GB)
     Array Size : 5236736 KiB (4.99 GiB 5.36 GB)
    Data Offset : 10240 sectors
   Super Offset : 8 sectors
   Unused Space : before=10160 sectors, after=0 sectors
          State : clean
    Device UUID : dcbc7209:b91588a7:184581a2:868371f4
  Update Time : Fri Sep  9 16:09:00 2022
  Bad Block Log : 512 entries available at offset 16 sectors
       Checksum : 4f461825 - correct
         Events : 17
 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 : ea4a83e1:dcc2457f:cdc92d4e:be46b105
           Name : linuxhelp:1  (local to host linuxhelp)
  Creation Time : Fri Sep  9 16:08:34 2022
     Raid Level : raid1
   Raid Devices : 2
 Avail Dev Size : 10473472 sectors (4.99 GiB 5.36 GB)
     Array Size : 5236736 KiB (4.99 GiB 5.36 GB)
    Data Offset : 10240 sectors
   Super Offset : 8 sectors
   Unused Space : before=10160 sectors, after=0 sectors
          State : clean
    Device UUID : 35d3f5fb:9c391eab:d431811d:27e16483
    Update Time : Fri Sep  9 16:09:00 2022
  Bad Block Log : 512 entries available at offset 16 sectors
       Checksum : 4f529cbf - correct
         Events : 17
 Device Role : Active device 1
   Array State : AA ('A' == active, '.' == missing, 'R' == replacing)

Step 8: Verify the md device status by using the below command

[root@linuxhelp ~]# mdadm --detail /dev/md1
/dev/md1:
           Version : 1.2
     Creation Time : Fri Sep  9 16:08:34 2022
        Raid Level : raid1
        Array Size : 5236736 (4.99 GiB 5.36 GB)
     Used Dev Size : 5236736 (4.99 GiB 5.36 GB)
      Raid Devices : 2
     Total Devices : 2
       Persistence : Superblock is persistent
       Update Time : Fri Sep  9 16:09:00 2022
             State : clean 
    Active Devices : 2
   Working Devices : 2
    Failed Devices : 0
     Spare Devices : 0
Consistency Policy : resync
              Name : linuxhelp:1  (local to host linuxhelp)
              UUID : ea4a83e1:dcc2457f:cdc92d4e:be46b105
            Events : 17
    Number   Major   Minor   RaidDevice State
       0       8       17        0      active sync   /dev/sdb1
       1       8       33        1      active sync   /dev/sdc1

Step 9: Create a filesystem for md device by using the below command

[root@linuxhelp ~]# mkfs.ext4 /dev/md1
mke2fs 1.45.6 (20-Mar-2020)
Creating filesystem with 1309184 4k blocks and 327680 inodes
Filesystem UUID: 4ac3a2e7-818d-4959-bee8-35a7d835fd6c
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736
Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done 

Step 10: Now permanently mount the md device by running the blkid command and copy the UUID number. Now create a fstab file using vim editor and enter the copied UUID number in the file. Save and exit the file.

[root@linuxhelp ~]# blkid
/dev/sda1: UUID="f7f9a415-4773-4386-8f26-53c0f2e67b14" BLOCK_SIZE="512" TYPE="xfs" PARTUUID="733bc0ae-01"
/dev/sda2: UUID="w7eHuA-nez8-zN5B-dl4t-7Orx-suzD-Xvd65u" TYPE="LVM2_member" PARTUUID="733bc0ae-02"
/dev/sdb1: UUID="ea4a83e1-dcc2-457f-cdc9-2d4ebe46b105" UUID_SUB="dcbc7209-b915-88a7-1845-81a2868371f4" LABEL="linuxhelp:1" TYPE="linux_raid_member" PARTUUID="e7a8668b-01"
/dev/sdc1: UUID="ea4a83e1-dcc2-457f-cdc9-2d4ebe46b105" UUID_SUB="35d3f5fb-9c39-1eab-d431-811d27e16483" LABEL="linuxhelp:1" TYPE="linux_raid_member" PARTUUID="249d77e5-01"
/dev/md1: UUID="4ac3a2e7-818d-4959-bee8-35a7d835fd6c" BLOCK_SIZE="4096" TYPE="ext4"
[root@linuxhelp ~]# mkdir /mnt/raid1
[root@linuxhelp ~]# vim /etc/fstab 
UUID=4ac3a2e7-818d-4959-bee8-35a7d835fd6c /mnt/raid1 ext4 defaults 0 0

Step 11: The device is mounted successfully and to verify the status of the device by using the below command

[root@linuxhelp ~]# mount -av
/                        : ignored
/boot                    : already mounted
none                     : ignored
mount: /mnt/raid1 does not contain SELinux labels.
       You just mounted an file system that supports labels which does not
       contain labels, onto an SELinux box. It is likely that confined
       applications will generate AVC messages and not be allowed access to
       this file system.  For more details see restorecon(8) and mount(8).
/mnt/raid1               : successfully mounted

[root@linuxhelp ~]# df -h
Filesystem           Size  Used Avail Use% Mounted on
devtmpfs             1.4G     0  1.4G   0% /dev
tmpfs                1.4G     0  1.4G   0% /dev/shm
tmpfs                1.4G  9.7M  1.4G   1% /run
tmpfs                1.4G     0  1.4G   0% /sys/fs/cgroup
/dev/mapper/rl-root   32G  5.5G   26G  18% /
/dev/sda1           1014M  255M  760M  26% /boot
tmpfs                276M   32K  276M   1% /run/user/0
/dev/md1             4.9G   20M  4.6G   1% /mnt/raid1

[root@linuxhelp ~]# lsblk
NAME        MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
sda           8:0    0   35G  0 disk  
├─sda1        8:1    0    1G  0 part  /boot
└─sda2        8:2    0   34G  0 part  
  ├─rl-root 253:0    0   31G  0 lvm   /
  └─rl-swap 253:1    0    3G  0 lvm   [SWAP]
sdb           8:16   0    5G  0 disk  
└─sdb1        8:17   0    5G  0 part  
  └─md1       9:1    0    5G  0 raid1 /mnt/raid1
sdc           8:32   0    5G  0 disk  
└─sdc1        8:33   0    5G  0 part  
  └─md1       9:1    0    5G  0 raid1 /mnt/raid1
sr0          11:0    1 1024M  0 rom  

Conclusion:

We have reached the end of this article. In this guide, we have walked you through the steps required to configure RAID 1 on Rocky Linux 8.6 has come to an end.