A UPS for your NAS: power, shutdown and restart

Size the complete load

List the NAS with its installed drives, any attached storage and the network equipment needed during the outage. Use an appropriate measured load or the equipment's documented requirement, including startup needs. An empty enclosure's consumption does not describe a populated NAS.

APC's sizing guide requires the connected load to stay within both the UPS's watt and VA limits. Those are output ratings, not minutes of runtime. Check the exact UPS's runtime chart at your expected load and allow time for shutdown plus a reserve. Battery condition and the connected load affect how long it can run.

Choose the required outcome: ride through a short interruption, or stop promptly and preserve battery reserve. Do not select a shutdown delay longer than the time the installed system can actually sustain. Check the regional voltage, plugs and which sockets provide battery backup against the exact UPS manual.

The UPS battery-backup comparison separates exact US revisions, manufacturer runtime estimates at 100 W and 200 W, backed outlets and replacement batteries. Read the UPS buying guide to apply those facts to a load and shutdown plan. The estimates do not measure your NAS or establish a tested pairing.

Confirm the data connection before buying

For one NAS, a supported USB monitoring connection is often straightforward: the NAS receives UPS status through a data cable as well as receiving electrical power. A charging port or a USB-shaped socket does not by itself prove supported UPS communication. Check the exact UPS model, NAS operating system and vendor compatibility record.

A network arrangement needs a supported management interface or a supported UPS server. Ethernet connectivity alone does not establish SNMP or network-UPS interoperability. Verify the actual protocol and settings in the documentation for both ends.

Use the NAS vendor's shutdown mode

• Synology DSM: for the DS225+ or DS925+, DSM 7 instructions cover USB UPS, SNMP UPS and Synology UPS server connections under Hardware & Power. Enable UPS support and choose the delay before Standby Mode. Standby stops services and unmounts volumes. Whether the UPS can then power off is a separate, model-dependent setting.
• QNAP QTS: the QTS 5.2 instructions offer USB, SNMP and Network UPS slave modes. Choose either power-off or auto-protection after a stated delay. Auto-protection stops services and unmounts volumes; QNAP documents resumed operation when power returns. The network UPS master option requires a USB-connected UPS.
• UGREEN UGOS Pro: for the DXP2800 or DXP4800 Plus, the Hardware & Power guide covers USB, SNMP and Network UPS Slave. Choose Standby or Auto Shutdown deliberately. Its reviewed instructions apply to UGOS Pro 1.10.0.0092 and above and warn that features can vary by version; confirm the settings on the installed release.

Do not treat these mode names as interchangeable. Check the resulting service state, volume state and power state. A NAS waiting in a protected state can behave differently from one that has fully powered off.

Keep network shutdown messages working

If several devices depend on a UPS server, its network path must survive the outage. Synology's network UPS instructions require the relevant switch or hub to be on the UPS. Account for that load when sizing the battery.

UGREEN's NUT server guide also explains why shutdown order matters: once the server NAS powers off, its UPS service stops. Configure client NAS systems to complete their shutdown before the server disappears, with a measured margin. Verify the permitted clients, addressing and protocol; this guide does not establish cross-brand server compatibility.

Test shutdown and restoration together

1. Finish and check a separate backup. Schedule the test when interruption is acceptable and avoid firmware updates, rebuilds or other sensitive storage operations.
2. Charge the UPS, confirm that the NAS identifies its model and battery status, and save the intended shutdown settings.
3. Follow the exact UPS and NAS manuals for a controlled outage simulation. Keep the NAS connected to the UPS's battery-backed output; do not test by cutting power directly to the NAS.
4. Observe the power-loss notification, shutdown or protected state and battery reserve. For network clients, verify that each receives the signal and completes its action in time.
5. Restore input power and check the expected restart, volume health, services and logs. Set automatic restart deliberately: DSM's restart-after-power-failure option is separate from UPS support.

UGREEN's USB setup instructions explicitly call for a simulated outage to verify shutdown. Repeat the relevant test after changing the UPS, battery, connected load or shutdown settings. Keep a record of the actual outcome rather than treating a detected USB device as proof of a completed shutdown.

A UPS does not supply another copy of your files. Keep the backup and restoration plan from the NAS storage guide, and use the drive guide to check the exact disks installed in the enclosure.