How to Create RAID Arrays with Mdadm
Here you will find out:
- how to create RAID array using mdadm
- how DiskInternals can help you
Are you ready? Let's read!
Mdadm for RAID
Ubuntu mdadm is a program with which you can create arrays and then manage them using the software features of Linux RAID. In fact, the administrator can create logical drives and manage them with significantly high write /read speeds and redundancy.
What you need to create RAID with mdadm
First, you must have admin rights (“sudo” privileges) on a Ubuntu server without root authority.
Second, you have a minimal level of RAID knowledge, including basic terminology, the main options of the array and their characteristics, etc. Your choice of storing data in arrays should be conscious and technically informed.
Third, you should have several disks (two or more), depending on what level of RAID you want. When using DigitalOcean, you can use Block Storage volumes as drives.
Now that you have everything you need to create an array, you can proceed.
Back up your data before resetting RAID!
Resetting the array will delete all the data written to it, without exception. Therefore, be careful with choosing the right RAID, and be sure to back up any necessary data before the array is reset.
To back up all your data, restore any data if necessary, and also create a disk image, you can use just one application: DiskInternals RAID Recovery. Its uniqueness lies in the fact that it does everything automatically: it checks the state of the array, file system, controller, disks, etc.
That is after you have selected the array to scan and the mode, recovery process starts. Very soon, you will see stunning results on the screen. In addition, each found file can be viewed for free so that you can confirm the unsurpassed quality of the recovery. Buying a license will give you the ability to export files anywhere. If you want to create a disk image, you will get one on a separate drive that you can use at the right time and restore the system with all the configurations and data.
- 1. Resetting RAID. After clearing out the array, you will probably want to use these drives again. To do this, remember that the data will be deleted after the reset of the array, so please save it or restore it using DiskInternals RAID Recovery.
- First find the active arrays. They are situated in proc/mdstat file.
- After that, unmount the array from the file system.
- Then stop the array. After that, delete it by typing “stop”.
- Now look for those drives that were part of the array. The names “/dev/sd*” can change with each reboot, so you must periodically check which devices with which names are used in the array. Check them every time to make sure that you are working on the right devices.
- As soon as these drives are found, reset the superblock. Thus, they will be returned to their normal state: zero.
- Next, update initramfs with the command:
$ sudo update-initramfs -u
Now your drives can be used again separately, as in the array.
- 2. If no RAID is set, you need to create a RAID (depending on the number of disks; you can create RAID 1-10).
This process consists of several steps:
- Identify the components that will be used to create the array.
- Create an array. To do this, you will need to specify the device name (for example / dev / md3), the number of disks, and the RAID level.
- Create a file system and then mount it so that it becomes available.
- Save the created array. In order for the array to be saved and automatically collected at boot, we need to configure the configuration file: etc/mdadm/mdadm.conf.