Thank you for checking in. This article will explain how to expand a NAS drive array capacity without data loss. But before we explain, let’s outline some assumptions. In this article we assume that a RAID 1 or a RAID 5 type array is configured in the NAS and that all drive bays are used, for a RAID 1, we assume two are used, and for a RAID 5, we assume four bays are used.
Now let’s also assume that the all disks used either by the RAID 1 or the RAID 5 are all 4TB each, and that you would like to expand the array to have 8TB drives.In order to do that without losing your data, you have different options, the simplest option is to copy all your data off the NAS device, destroy the current configuration, insert the new disks all at once, configure the array for maximum capacity, and finally copy the data back the the array. While this is the simplest approach, it also comes with a few drawback:
- All configuration is lost and has to be recreated, file permissions, maybe users and groups, depending on the NAS you use.
- Also you will need a lot of space to perform a temporary copy of your data, not everyone has that much space available for the copy.
- Plus while the new drives are configured, you lose the redundancy and potentially can lose all the data
The other and more secure approach is going to take a little longer, but redundancy is mostly maintained during the process and no reconfiguration is necessary. Let’s now explain the steps. Let’s describe the process on the RAID 5 configuration, but the same applies on the RAID 1, only simpler. First of all we are going to assure that the new capacity is supported by the NAS, secondly, we are going to purchase all the disks required for the upgrade, so if you are upgrading a 4TB 4-disk bay to a 8TB 4 disk bay, you will need 4 new 8TB disks.
Once you have the disks in your possession, we are going to make sure that no bad disks are present in the current configuration, if you have a bad disk, you would start with that disk, but the process is the following:
- Turn the NAS off cleanly (NAS has a clean shutdown)
- Open the disk bay or simply unplug one drive, (ONLY ONE DRIVE)
- Take note of the drive that you unplug
- Put the new drive back in
- Turn the NAS on
- The NAS will automatically rebuild the drive array, this will take a while depending on the NAS you are using.
- When the process is complete, move to the next drive
- Repeat the process until all drives have been replaced
You will need to login to the NAS console to observe the rebuild operation, make sure it finishes before continuing with the next drive.
When all drives are done, now you have the same size array with new drives, the new capacity is not available yet. You will have to perform an expand operation to use all available space. The operation changes depending on your NAS vendor. Consult the NAS documentation for assistance.
In the end, you will have the total new capacity without any data loss and massive reconfiguration.
This article meant only to outline the general process and not any specific process; there are just too many NAS vendors to outline all of them. But the overall steps are the same.
Thank you for reading this article and I hope you will come back.