A few years ago when I built my Synology NAS I threw in four 1 TB hard drives. At the time this was the biggest bang for my buck. However, with the price of hard drives falling, it was time for an upgrade. Not to mention that my NAS was just about full and I really needed more space.
I decided to get some Western Digital Red 3 TB Drives (Model: WD30EFRX). While this isn’t a review of these drives, I must say that these drives are impressive. They are amazingly quiet. With all four of them in the NAS you have to literally put your ear up to the device to hear them spin or read/write. I HIGHLY suggest these drives for your NAS. I hope this goes without saying, but you need to make sure your new drives are all the same size. There are several theories on selecting drives that are produced in different batches. This will help eliminate the risk of multiple drives failing at the same time if they were part of a bad batch of drives in production. If you are that cautious you can research that and try to buy your drives at different times of the year. I’m far too impatient for that.
The game plan for the upgrade was simple: manually replace one drive of the RAID 5 with a new 3 TB drive, rebuild the array and repeat. Replacing one drive will cause the RAID to be in a degraded state until it rebuilds on the new drive. This should protect my data and replace the old drives with the new ones. After the NAS has all 4 new drives I would expand the volume to utilize the new space added. This takes some time but it’s a pretty simple way to do this. Synology has a tutorial here. In short here was the plan:
Upgrade and replace NAS Hard Drives in RAID 5
- Power down the NAS.
- Pull one old drive out and replace with a new drive.
- Power on the NAS.
- Log into the user interface and repair your RAID.
- Repeat this process by going through all the drives.
- Finally go to your RAID management and expand the volume to utilize the full hard drive space available. Some NAS’ will do this automatically.
So the above is the ideal situation. Unfortunately I ran into some troubles. At stage 4 of my steps, when I went to repair the RAID onto the new 3 TB drive, I got an error that said the version of my Volume1 did not support drives over 2 TB. When this happened I didn’t know quite what that meant. After doing some research it turns out that my NAS supports the larger disks, however the Volume I created back when I first got the NAS did not. Since I had upgraded the DSM over that time the NAS supports the disks but the volume doesn’t. The error I received was:
The volume is created with a previous version of DSM which does not support hard disks larger than 2TB. To use hard disks larger than 2TB, please create a new volume with the latest version of DSM
After scratching my head for a while a solution finally came to mind. This is risky because during this time the NAS is in a degraded state and I don’t have data redundancy. However, I realized that I had three 1 TB drives with all my data and one 3 TB drive that was blank. The math added up so I decided to backup all my data from the RAID to a single disk. Then replace all three remaining drives at once, create the new volume with the updated version, and then expand it to my fourth drive. In short here was the solution:
Create new Volume for larger drives without losing data:
- Take your existing RAID 5 with four disks and power it OFF.
- Replace one of the disks with the new hard drive that is larger than your Volume supports. (In my case it was the 3 TB drive)
- Power ON the NAS.
- Create a new volume (Volume 2) on the new hard drive.
- Copy your data from the RAID array Volume 1 to Volume 2. You can do this with the Synology “Backup and Restore” application directly on the DSM. Do a local backup from Volume 1 to Volume 2.
- Once the backup is complete power OFF the NAS.
- Replace the remaining Hard Drives.
- Power ON the NAS
- Initialize the three new disks and create a RAID 5 with them. (This will take a long time with larger disks.)
- Once the new RAID 5 is created, create a new volume on it and label it Volume 1.
- Use Synology Backup and Restore to restore your backup from Volume 2 onto Volume 1.
- Once the Restore is complete Delete Volume 2.
- Reboot the NAS
- Go into your Storage Manager, select Volume 1 and Manage it.
- Expand Volume 1 onto the fourth disk that is now empty. (This will take a very very long time. Took mine about 5 days.)
Once everything is complete you should have your original data all back on a four drive RAID 5 with the new 3 TB hard drives. During this upgrade I want from 4 x 1TB drives that gave me about 2.8 TB of storage in RAID 5 to 4 x 3 TB drives that gives me 8.2 TB of storage. Needless to say I am hopeful I won’t have to upgrade for another few years.