How to Back Up a Synology NAS to Backblaze B2 Without Paying for a Third-Party App

If you have a Synology NAS sitting in your home and you’re not backing it up offsite, you’re one house fire or ransomware attack away from losing everything on it. That’s not hyperbole. A NAS with no offsite backup is just a more expensive way to lose your data.

The good news is that Synology’s built-in Hyper Backup app supports S3-compatible storage, which means it works directly with Backblaze B2. No third-party apps. No monthly subscription to a polished backup service. Just a B2 account, your NAS, and about 45 minutes to get everything configured properly.

Here’s exactly how to do it.

Why Backblaze B2 Is the Cheapest Offsite Option for Under 10TB of Family Data

Backblaze B2 charges $6 per terabyte per month for storage, with the first 10GB free. Downloads (egress) cost $0.01 per GB, but Backblaze has a free egress allowance that covers most restore scenarios under normal conditions.

Compare that to Amazon S3 at roughly $23 per TB per month, or Google Cloud Storage at $20 per TB per month for standard storage. For a family sitting on 3-4TB of photos, documents, home videos, and media, B2 costs around $18-24 per month. That same data on S3 would cost $70-90 per month.

Wasabi is a closer competitor at $6.99/TB with no egress fees, but B2’s Hyper Backup compatibility is better documented and more widely tested by the Synology community. For families who want a proven setup without troubleshooting edge cases, B2 is the better starting point.

One thing to plan for: Backblaze B2 bills for what you store, including old versions. If you configure Hyper Backup to keep 10 versions of a 2TB dataset, you’re potentially storing 20TB. Think about versioning before you start uploading.

If your NAS is filling up and you’re wondering whether an 8TB drive makes more sense than a 4TB, the capacity decision breakdown here is worth reading before you commit to a storage tier on B2.

Setting Up a B2 Bucket and Application Key: What Not to Skip

Before you touch Hyper Backup, you need two things from Backblaze: a bucket and an application key. Getting these wrong is the most common reason the setup fails.

Creating the bucket:

1. Log into your Backblaze account and go to B2 Cloud Storage > Buckets.
2. Click Create a Bucket.
3. Name it something you’ll recognize, like synology-hyper-backup. Bucket names must be globally unique across all B2 accounts, so add a random string if needed.
4. Set it to Private. Do not make it public.
5. Enable Object Lock only if you specifically want immutable backups (ransomware protection). It adds cost and complexity. For most home setups, leave it off.
6. Leave the default encryption settings unless you have a specific reason to change them.

Creating the application key:

This step is where people make mistakes. Do not use your master application key for Hyper Backup. Create a dedicated key with limited permissions.

1. Go to Account > Application Keys.
2. Click Add a New Application Key.
3. Give it a name like synology-hyper-backup-key.
4. Under Allow access to Bucket(s), select only the bucket you just created.
5. Set Type of Access to Read and Write.
6. Leave Allow List All Bucket Names unchecked unless Hyper Backup specifically requires it (some S3 clients do). Test without it first.
7. Click Create New Key.

Copy the application key immediately. Backblaze shows it exactly once. If you navigate away without copying it, you’ll need to delete the key and create a new one. Store it somewhere secure before continuing.

You’ll also need your keyID (shown on the same screen) and the endpoint URL for your bucket. The endpoint looks like s3.us-west-004.backblaze.com and varies by region. Find it by clicking on the bucket and looking at the Endpoint field under bucket details.

Configuring Hyper Backup with B2-Compatible S3 Settings

Hyper Backup doesn’t have a native Backblaze B2 option, but B2 is S3-compatible, which means the S3 Storage destination type works. Here’s the exact configuration.

In DSM:

1. Open Package Center and confirm Hyper Backup is installed. On most Synology models running DSM 7.x it’s pre-installed.
2. Open Hyper Backup and click the + icon to create a new backup task.
3. Select Data backup task, then choose S3 Storage as the destination.

On the destination configuration screen:

• S3 Server: Select Custom Server URL
• Server address: Paste your bucket’s endpoint URL (e.g., https://s3.us-west-004.backblaze.com)
• Signature version: Set to AWS Signature V4
• Access key: Paste your B2 keyID
• Secret key: Paste your B2 application key
• Bucket name: Type your bucket name exactly
• Directory: Set a subdirectory name like hyper-backup to keep things organized

Click Next and Hyper Backup will attempt to connect. If it fails at this step, the most common culprits are a wrong endpoint URL, a typo in the key, or a bucket permission issue. Double-check that your application key has Read and Write access to the correct bucket.

Selecting what to back up:

On the next screen, select the folders you want to include. Be deliberate here. Backing up everything including Docker volumes, package data, and temporary directories inflates your B2 storage costs. Focus on:

• Personal folders (photos, documents, home videos)
• Critical shared folders
• Application data for anything you’d want to restore (note that application backup requires selecting specific apps in the next step)

If your NAS is underpowered for the task, the entry-level constraints analysis of the DS220J explains why backup performance varies significantly by model.

Scheduling, Versioning, and How Many Versions Are Actually Worth Keeping

Scheduling:

For most home setups, a nightly backup at 2 or 3 AM works well. Hyper Backup runs incrementally after the first full backup, so subsequent runs are faster and use less bandwidth.

If you’re on a metered internet connection, set a bandwidth throttle under Transfer Settings. Hyper Backup lets you cap upload speed so a large backup doesn’t saturate your connection during the day.

Versioning:

This is the most important setting to think through before you hit save. Hyper Backup defaults to keeping multiple versions, and every version stored in B2 costs money.

Here’s a practical framework:

• 5 versions is the minimum worth keeping. It protects you from realizing a file was corrupted or deleted and not noticing for a few backup cycles.
• 10-15 versions is a reasonable middle ground for most families. At a nightly schedule, that’s roughly 2 weeks of rollback capability.
• 30+ versions adds meaningful protection against slow-moving ransomware or gradual file corruption, but roughly doubles your B2 storage costs.

Under Rotation Settings, Hyper Backup offers Smart Recycle, which keeps more recent versions at higher frequency and older versions at lower frequency. This is generally the best option for home use because it balances storage cost against the realistic scenarios where you’d need to restore.

Set a version retention limit explicitly. If you leave it unlimited, your B2 costs will grow indefinitely as versions accumulate.

Testing Your Restore Before Disaster Does It for You

Most people configure a backup and never test it. Then when they actually need it, something doesn’t work. Do not be that person.

How to run a restore test:

1. In Hyper Backup, click the restore icon (the circular arrow) for your B2 task.
2. Select Restore > Data.
3. Choose a specific folder you don’t mind overwriting temporarily, or restore to an alternate location.
4. Select a version from the timeline and restore a small subset of files.
5. Confirm the files are intact and readable.

This process also confirms your B2 application key is working for reads, not just writes. A key misconfiguration that only breaks downloads is easy to miss until you’re in a recovery situation.

Also test the backup integrity check:

Hyper Backup has a built-in integrity check feature. Right-click your backup task and select Check backup integrity. This verifies that the backup data in B2 is valid and can actually be restored. Schedule this to run monthly. It uses some B2 download bandwidth but it’s worth it.

One more thing to verify: your B2 bucket still exists and hasn’t been accidentally deleted. Log into Backblaze every few months and confirm the bucket is there, the data size looks right, and your key is still active. Application keys can be deleted or expire if you set a duration limit when creating them.

The Storage Foundation Underneath All of This

Offsite backup only protects you if your NAS drives are also reliable. Backblaze’s own internal drive reliability reports, published annually, have informed the NAS drive market for years. If you’re running consumer desktop drives in your NAS, you’re already operating with more risk than you should be.

The Seagate IronWolf 8TB runs at 7200 RPM with a 256MB cache and is rated for 24/7 NAS operation with a 1 million hour MTBF rating. At $299, it’s a reasonable investment for a drive that’s actually designed for the always-on, multi-user workload that a family NAS creates. It also includes three years of Rescue Data Recovery Services, which is a meaningful addition for a drive holding data you care about.

Good drives reduce the likelihood you’ll ever need that B2 restore. But “reduce the likelihood” is not “eliminate the risk,” which is exactly why the offsite backup exists.

The total cost for this setup is your Backblaze B2 storage charges and nothing else. For 3TB of backed-up data with 10 versions retained, expect to pay in the range of $18-25 per month depending on how much version data accumulates. That’s a reasonable price for offsite protection that you fully control.