Backing Up Large Numbers of Small Files to Another QNAP NAS: Use Snapshot Replica
Applicable Products
NAS (QTS / QuTS Hero)
Scenario
While backing up large numbers of small files, like tens of thousands to hundreds of thousands of small files to another NAS, file-based methods (RTRR / rsync) must scan directories, open/close files, and compare metadata for each object—costs that dominate when files are tiny.
Solution
Use snapshot-based replication. Below is the recommended approach with measured results.
Test environment (for reference)
Source NAS: TS-h1677AXU-RP (QuTS hero h5.2.6.3195, 2025/07/15)
Destination NAS: TS-h1677AXU-RP (same)
HBS 3: V26.0.1.723
Measured summary: 100,000 small files (total 138 GB)
| Method | Throughput | Rough completion time* |
|---|---|---|
| Snapshot Replica | 1.00 GB/s | ≈ 2m 18s |
| SnapSync | 1.16 GB/s | ≈ 1m 58s |
| RTRR | 225.87 MB/s | ≈ 10m 10s |
| rsync | 219.98 MB/s | ≈ 10m 27s |
What this means
On this setup, Snapshot Replica/Snapsync was ~4.4–5.1× faster than RTRR/rsync for very small files. Between two QNAP NAS, snapshot-based replication shifts the work to block-level changes, dramatically reducing per-file overhead.
Decision rule
Both NAS run QuTS hero → use SnapSync (near-real-time replication; fastest in this test).
Otherwise → use Snapshot Replica (SnapSync requires QuTS hero on both source and destination).
