RAID5 Array configuration - and mount it to an Amazon EC2 instance as the additional storage (Raid 5 Configuration)

 

Create a RAID5 Array and mount it to an Amazon EC2 instance as the additional storage

By: Udara Pathirage on 7^th Jan 2021

1. Create an EC2 instance using the AWS Console- using default settings.

2. SSH in to the instance

    a) Check the current disk details

              i) $df –h

    b) List the currently attached Hard disk drives, $lsblk

c) See the partition details; $fdisk –l

3. Create 3 volumes using the AWS Console; Magnetic is the cheapest to make the tests.

a) Select the Availability Zone where the App Instances has hosted. Otherwise, it will not be able to mount
b) For the RAID5, minimum of 3 hard disks required
c) Clone settings of Volumes
d) Give the name of ‘device’ as ‘sdb’, ‘sdc’, ‘sdd’ ,so on
i) First check whether there are hard disks available in the names that we are going to create in the next steps - $fdisk –l
e) RAID 5 Total capacity of RAID of having 1TB 3 HDD will give only 2TB due to keeping 1TB as a backup.

Check how new hard disks have attached to the instance. Type $fdisk -l  to view from the terminal.

4. Create the RAID Drive

a) Go into each partition and map it into the RAID Drive
            i) $fdisk /dev/sdb

(1) Add new partition clicking ‘p’.

(2) Create a full disk partition

(3) Click ‘t’.

(4) Select ‘fd’ (Linux Raid auto)

(5) Click ‘w’ to write the settings

ii) Repeat above process to the all hard disks

iii) You can see the created partitions using: $fdisk –l

Type $fdisk -l to see the created partitions on each disks

5. Creation of RAID drives

i)        $mdadm –E /dev/sd[a-d]

(1)    All HDDs starting from “a” to “d”

ii)       create the RAID Drive name as “md0”

(1)    $mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1

(a)    –md0 is the raid volume name

(b)    --level=5 > RAID 5 configuration

(c)     --raid-devices=3 >> how many devices going to add into this RAID

(d)    /dev/sdb1 /dev/sdc1 /dev/sdd1 >> devices we created at last steps

(2)    You will see a notice as “/dev/md0” started >> you have created the RAID array successfully.

How to verify the RAID is in active

(1)    $cat /proc/mdstat

(2)    $watch /proc/mdstat

(3)    $mdadm --detail /dev/md0

Next, the Above step has to be completed, 100%.

6. Create a filesystem on the Raid Device and mount it to the /opt 

• mkfs.ext4 /dev/md0
• mount /dev/md0 /opt/
• df -h

Now you can see it has mounted into /opt successfully.

6.A How to mount permanently. No matter reboot. After the reboot, this drive will automatically be mapped

Terminal: $vi /etc/fstab

add a following entry as here

(1) /dev/md0 /opt ext4 defaults 0 0

My code block

 

[root@ip-172-31-20-67 opt]# history
    2  df -h
    3  lsblk
    4  fdisk -l
   13  fdisk /dev/sdb
   14  fdisk /dev/sdc
   15  fdisk /dev/sdd
   16  clear
   17  fdisk -l
   18  clear
   19  mdadm --help
   20  mdadm -E /dev/sd[a-d]
   21  clear
   26  mdadm --create /dev/md0 --level=5 --raid-devices=3 /dev/sdb1 /dev/sdc1 /dev/sdd1
   27  cat /proc/mdstat
   28  clear
   30  sudo watch /proc/mdstat
   33  mdadm --detail /dev/md0
   41  cat /proc/mdstat
   42  mkfs.ext4 /dev/md0
   51  mount /dev/md0 /opt/
   52  cd /opt/
   53  ll
   54  df -h
   55  vi /etc/fstab
   57  cd /opt/
   58  ll
   59  mkdir test1
   60  mkdir test 2
   61  ll
   62  touch file1 file2 file3 file4
   63  ll
   64  lsblk
   65  history
[root@ip-172-31-20-67 opt]#

Done, You can use this RAID5 device with ONE disk failure facility.

References:

a)       1. https://www.youtube.com/watch?v=xjCBEjFujvI

b)    

2.   https://www.youtube.com/watch?v=RdHBEyFqLn0

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