Synology NAS, like other servers and storage mediums, is capable of running hard drives in what’s known as a redundant array of inexpensive drives (RAID). What this does is allows an OS to combine multiple drives into a single virtual volume and helps protect against data loss in the event of hardware failure. But which RAID is best?
What is RAID?
In the most basic sense, RAID is the formation of the best NAS drives into a single volume. While this does not automatically provide protection, there are RAID types that involve the duplication of data across disks to avoid data loss in the event of a drive failure.
If a drive fails and it’s not part of a RAID configuration, you’ll lose all stored data. Should a backup copy not be available, you’re out of luck. In a RAID, a faulty drive could be replaced and the stored backup data could then be used to recreate the storage volume, allowing you to continue as if nothing happened.
RAID does mean you lose some of the capacity due to part of the volume being reserved for storing the necessary data for use in recovering the volume. I find this tradeoff well worth the return in data protection and storage volume stability.
What’s the best RAID for Synology NAS?
Since we have different levels of RAID, as well as Synology’s on Synology Hybrid RAID (SHR), which is the best to use on a NAS? This depends on how many drives you plan to use and what levels of protection you require if any. I’d recommend SHR for most Synology NAS.
| RAID | Drives | Tolerable failures | Data redundancy | Capacity | Notes |
|---|---|---|---|---|---|
| Basic | 1+ | 0 | ❎ | HDD size | |
| SHR | 1+ | 0 – 2 | ✅ | Varies | No protection with single drive SHR |
| 0 | 2+ | 0 | ❎ | HDD size | |
| 1 | 2+ | 1 – 3 | ✅ | HDD # -1 x smallest HDD size | |
| 5 | 3+ | 1 | ✅ | HDD # -2 x smallest HDD size | |
| 6 | 4+ | 2 | ✅ | HDD # -2 x smallest HDD size | |
| 10 | 4+ | 2+ | ✅ | HDD # -1 x smallest HDD size | HDDs must be even number, tolerable to half the number of HDDs |
Synology Hybrid RAID offers ample protection for NAS with at least two drives. I wouldn’t recommend basic or RAID 0. Remember that RAID does not guarantee the protection of your data. Always store backup copies elsewhere.
How to change RAID on Synology NAS
Synology DiskStation Manager actually allows one to change the RAID on a NAS. It’s not a process that can switch between normal RAID and Synology Hybrid RAID, and the normal levels need to fall in the below table for it to be possible.
| Old RAID | New RAID | # of new drives required |
|---|---|---|
| Basic | 1 | 1 |
| Basic | 5 | 2 |
| 1 | 5 | 1 |
| 5 | 6 | 1 |
| SHR-1 | SHR-2 | 1 – 2* |
With RAID set up and working on your Synology NAS, you’ll be better protected against drive failures. I’d recommend choosing the best NAS drives available on the market, as opposed to the old desktop-class HDDs you have laying around.
Seagate IronWolf
I’m a big fan of Seagate’s IronWolf series of NAS hard drives. If you’re serious about storage, the Pro range offers a few advanced extras.
Western Digital Red Plus
Western Digital makes some of the best drives on the market and its Red Plus range for NAS enclosures is no exception. You’ll have a wide range of options to choose from.
