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Creating and Managing a Software RAID

RAID is used to combine multiple devices into one or more logical units. In this hands-on lab, we are tasked with creating a RAID 5 array, failing active devices and observing the behavior, and adding new devices to the RAID to replace the ones that have failed.

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Path Info

Level

Intermediate

Duration

30m

Published

Jul 24, 2020

Challenge

Create a RAID 5 Array Based on the Instructions
Use the mdadm command to create the RAID 5 array.
```
mdadm -C /dev/md0 -l raid5 -n 3 /dev/xvdf1 /dev/xvdg1 /dev/xvdj1 -x 3 /dev/xvdf2 /dev/xvdg2 /dev/xvdj2
```
Create the mdadm.conf file to ensure the RAID is available on boot.
```
mdadm -D -s -v > /etc/mdadm.conf
```
Challenge

Create an Ext4 Filesystem, Mount It, and Ensure It Persists Through a Reboot
Use the mkfs command to create an ext4 filesystem on /dev/md0.
```
mkfs -t ext4 /dev/md0
```
Create the /mnt/raid mount point.
```
mkdir /mnt/raid
```
Mount /dev/md0 on /mnt/raid.
```
mount -t ext4 /dev/md0 /mnt/raid
```
Use the blkid command to obtain the UUID of /dev/md0:
```
blkid /dev/md0
```
Use a text editor to open /etc/fstab and add the following entry at the bottom of the file (using the UUID observed in the previous step):
```
UUID=uuid_of_md0    /mnt/raid    ext4    defaults    0 0
```
Challenge

Fail the Active Devices in the Array One at a Time and Remove Them
Fail the active devices using the -f option (Note: Wait until a spare device has been added to the array before proceeding to the next to prevent RAID failure. The state can be checked by running mdadm -D /dev/md0).
```
mdadm -f /dev/md0 /dev/xvdf1
mdadm -f /dev/md0 /dev/xvdg1
mdadm -f /dev/md0 /dev/xvdj1
```
Remove failed devices from the array.
```
mdadm -r /dev/md0 /dev/xvdf1 /dev/xvdg1 /dev/xvdj1
```
Challenge

Add Three New Devices to the Array Based on the Instructions
Add new devices to /dev/md0.
```
mdadm -a /dev/md0 /dev/xvdf3 /dev/xvdg3 /dev/xvdj3
```
Update /etc/mdadm.conf with new configuration changes.
```
mdadm -D -s -v > /etc/mdadm.conf
```

Author

A Cloud Guru

The Cloud Content team comprises subject matter experts hyper focused on services offered by the leading cloud vendors (AWS, GCP, and Azure), as well as cloud-related technologies such as Linux and DevOps. The team is thrilled to share their knowledge to help you build modern tech solutions from the ground up, secure and optimize your environments, and so much more!

What's a lab?

Hands-on Labs are real environments created by industry experts to help you learn. These environments help you gain knowledge and experience, practice without compromising your system, test without risk, destroy without fear, and let you learn from your mistakes. Hands-on Labs: practice your skills before delivering in the real world.