Is it possible to upgrade the hard drives in a My Cloud Mirror NAS?

Question

I recently bought a WD My Cloud Mirror NAS which includes 2 2TB hard drives running in RAID 1 by default. That effectively gives me 2TB of storage space which is plenty for now. I know I will eventually run out, though, and when I do, I'd like to be able to increase the capacity while keeping everything contained within one unit. One of the features of the device is being able to increase the capacity by plugging in external USB drives but I would rather not do that. If anything, I would rather reserve that feature for performing backups for offsite storage.

I'm a little annoyed (especially by WD) that I can't find any information on this topic, even on their community forums. The only information I can find is on replacing failed drives. It seems like a no-brainer for me. Why would anyone replace an entire NAS just to upgrade the storage capacity when the drives are replaceable? My guess is that they can be upgraded and here's how I think it can be done: Replace one drive, let the RAID rebuild, replace the other, then expand the volume. I'm not sure about a few things though. Does the device support larger drives than the original ones, can you upgrade them one at a time, and if it's even possible, how do you expand the volume? Is it automatic or do you have to do it manually?

I'm just not sure about all this. I have an idea but I'm not willing to buy new drives unless I know it will work.

Solution 1

With RAID 1, both drives MUST be the same size. So if you're upgrading the drives, then you can't just rip one out, put one in and expect it to rebuild. However, if the drive is the same size it should work fine. But seeing as you're wanting to expand the volume, it's not going to work. You're going to need to backup your data onto an external device, take out your hard drives (both of them), put your new drives in, create the new RAID array then put your stuff back on.

The TL;DR version: You can't mix hard drive sizes with RAID 1, which means you cannot expand the RAID volume.

Solution 2

The TL;DR version: You can't mix hard drive sizes with RAID 1, which means you cannot expand the RAID volume.

That's not true. You can mix drive sizes in RAID. You just end up being limited by the smallest size drive. If you make a RAID 1 set with a 2TB and an 8TD drive, you would have 2TB usable. Likewise, the drives can have different speeds (10k rpm and 15k rpm) and they'll just be restricted by the slowest drive.

Maybe WD has some sort of proprietary restriction, but RAID absolutely allows you to use different drive sizes.

Solution 3

I just did this very thing. I had two 2tb drives in My Cloud Mirror. I bought two 4tb drives. To replace each drive, I put the NAS into hibernation, then swapped one of the 2tb for a 4tb drive. After a few hours, the NAS rebuilt the volume automatically. Then I did the same thing again for the other drive and the whole volume was rebuilt again.

After this, you can go into the "Storage" tab, then go to change raid mode. In that dialog, select to expand storage. Since your new drive is already installed, don't select to add new drive. Go through the options and the NAS will automatically expand your volume.

Comments

[elviswjr]

Thanks for the answer. This is my first time using a NAS or any kind of RAID setup so I didn't know. My only other concern is if it's possible for the device to have some kind of built-in limit on the capacity of the hard drives. The reason I'm wondering is because I can't find any documentation on upgrading other than plugging in external drives.

[Bilfred]

Most consumer NASes do have built-in limits, although it's usually 3/4TB per drive. An 8TB limit is fairly common, especially for 2 drive units. If my answer helped you, it would be great if you could select it as the answer

[TextGeek]

A bit late, but you should be able to remove the old drives from the RAID box entirely without copying them first. Just pull them out, install the new drives, and format the new ones as if the old ones never existed. Then plug one of the old drives into some box on your net and copy it onto the new RAID. No need to copy it somewhere else first.

[elviswjr]

Thanks for the info. It was a couple of years when I posted this so I've since addressed this issue (sort of). I bought an external USB drive for backup and I switched the NAS drives to RAID 0 for enough extra space until I can afford to replace them completely. At this point, I'm probably going to upgrade to an entirely different NAS enclosure with enough drive bays to add more in the future.

[santiagozky]

do you loose any data in the process?

[Toby]

just wanted to comment for @santiagozky - no you dont lose data, thats the whole idea behind a raid over 2 drives that when one breaks you can replace it without losing any data. hence if he removes one, adds a new one, the missing data is recreated, when he does the same with the other drive, the other half is recreated.