 Hello everybody! Watch this video to find out how to add a new drive and expand an existing RAID array without losing data. In this video, I'm going to show you how to expand a hardware RAID build on a controller or NAS and how to expand a software RAID in a Linux operating system. When RAID runs out of free space, it is time to consider available options to expand your storage. It means adding more drives to the array, if such option is supported by the service hardware. Otherwise, you can rebuild the array with the drives of larger capacity. If a server has a free slot for another HDD, then you can expand the existing RAID system without losing any data at all. In a minute, we'll explore how to add a hard disk to an array based on a controller or build on a NAS storage system with the example of a QNAP unit. How to do it on a software Linux base grid created with the help of MDADM and LVM utilities or on the array created with the means of better-of-est file system? In our channel and blog, you will find solutions to any problem from installing an operating system or configuring it to fixing possible bugs and errors or optimizing mobile gadgets. Our specialists will answer any questions you ask in your comments under the videos or articles. For starters, let's see how to add a new disk to a hardware RAID based on a dedicated controller. Some controllers support adding new hard disks to the existing RAID 5 and 6 systems, which allows to expand the disk array in order to have more storage space for your files. In our example, we'll be expanding a RAID 5 with 3 drives to get a RAID 5 with 4 drives. Let's begin with connecting the new drive to the server. After that, go to the controller's bias or RAID management utility. Keep in mind that some controllers may not support adding new drives, so it's always a good idea to check your storage device manual for details. All the data on the new drive will be erased. Also, we recommend creating a backup copy of important files stored on your RAID. In the RAID management utility window, select the controller and then the array that needs to be expanded. Look to the right to find and select the option Expand Array. After that, choose the drive to add to the array and click Save. It starts the array expansion process and you can see the status here. Wait until the rebuilding is complete. When it's over, some unused space will appear in your array and you should add it to the logical drive. Select the logical drive you want to extend and click Extend Logical Drive on the right. Choose the maximum size here or set another value and then click Save. After that, the process of rebuilding the array begins. When it's over, the array capacity will increase. Meanwhile, all your data on the array disks will be left intact. If a specific drive doesn't appear on the list, it might be unsuitable for adding to the array. For example, its capacity could be lower than that of any other drive within the array. Or the drive was not formatted for this operation. It can also belong to another disk array or was configured as a hot swap drive. Now, let's explore how it can be done with a NAS device. If your NAS storage has an empty slot for one more HDD, you can easily expand the capacity of your virtual drive by adding a new hard disk. To do it, connect the hard disk to the NAS, boot it and open the Storage Management Panel. After that, open the menu and access Storage Manager – Storage Pool. Click on the Action button and select Add Disk from the list. In the window that opens, add the new disk to the existing array and click Next. When you do that, there will be a warning that all information on the disk is going to be erased. Click OK to confirm this action. At the next stage, check the properties and click Apply. It starts the initialization process, but the disk will be available even now, so you can continue working with the storage. When the initialization is over, the last step is to expand the rate. To do it, open Volume, then go to Action, Configure, and in the window that opens, enter the necessary size and click OK. Wait until the expansion operation is over and check the data that was stored on the disks. As you can see, all the files are still there. Now let's explore how to add a drive to MDRAID 5 without losing data stored on the disk array. In Linux Subunter, I have built a software RAID 5 consisting of three disks using the MDADM utility. I need to add another hard disk of the same size to this array. For starters, we have to prepare a disk. Let's identify the disk that needs to be added and type this command. After that, I have to create a partition on the disk. N stands for New, P stands for Primary, and 1 stands for Partition Number. Leave other settings without changes and press Enter twice. Record changes by pressing W button. Now that the disk is partitioned, add it to the existing RAID 5 array by using disk command. Check the RAID. As a result, the disk was added as a spare device. To expand the array with this new disk, you need to type the following command. This command tells the system that the RAID makes use of four hard disks. This way, the command initializes RAID rebuilding since the information has to be spread across all the hard disks. This process takes some time, so wait until it is over. To have its status displayed, there is a special command. The actual reshaping process will be shown here. Now, the RAID consists of four hard disks, but its size is still equal to 100 GB. To be able to use the 50 GB available on RAID 5, you'll have to change the file system size. First, run the integrity check. After the separation is completed without errors, the file system can be extended. You can do it with the help of the tool called Resize to FS. Mount the disk and check it. The partition has been extended, and you can see that all the files are still there. Now, let's find out what can be done to another type of software RAID built with the LVM utility. I have an LVM RAID 5 consisting of three hard disks, and I'd like to add one more. In this case, it should be prepared and partitioned. I'm going to show you how to do it with the fdisk utility. For partitioning, type the following command. And specify the disk name here. N stands for new, P stands for primary, and 1 stands for partition number. Leave other settings without changes and press Enter twice. Record changes by pressing the W key. After that, create a virtual disk on this HDD by using another command. And then use this virtual disk to extend the VG1 group with this command. Check the properties of the virtual group. And finally, type the command to expand the RAID 5 logical volume. Then extend the file system on the logical volume. Open the disk utility and check the RAID properties. As you can see, now the RAID consists of four hard disks. As we open the disk, you can see that the files remain unchanged. There is one RAID system created with the help of BF file system. It consists of three hard disks, and we are going to add another hard disk of the similar size. The files stored on this RAID will not be raised. To expand the software BF RAID, we'll use the command BF device add. To add a storage device to the mounted file system, run this command. After the device is added, it is recommended to balance the BF file system. To do it, type this command in the terminal. When we check the RAID, with the disk utility, you can see that the size has increased. And the files stored on the disk RAID have not been raised. Summing up, we have just explored several ways of expanding a RAID. Following our video tutorial, you'll be able to save the data which is stored on your RAID system. But even if your RAID has crashed, and you have lost access to the files stored on that disk RAID, you will always be able to restore them with the help of the specialized tool – Hetman RAID Recovery. In our previous videos, we have studied in detail the process of recovering data from all RAID types mentioned in this video, so just check the links in the description below. And that is all for now. Hopefully, this video was useful. Remember to click the Like button and subscribe to our channel. Leave comments to ask questions. Thank you for watching. And good luck.