You need a Uninterruptible Power Supply (UPS) for your Synology NAS. Well, any NAS actually, but around here we’re all Synology. Even if, like me, you live in an area with generally reliable power it’s only a matter of time before there’s a power problem with your always on Synology NAS. If that time is an extended power outage the UPS can tell the Synology NAS to safely power down before it drains the battery completely.
In addition to providing battery backup for those short power interruptions the UPS can, depending on the model, also protect against voltage spikes, surges, brownouts, power sags (similar to brownouts, but shorter) and EMI or RFI noise.
The Synology is running the drives in a RAID configuration, even the slightest power hiccup could crash the array. The NAS will have to go through a process to rebuild the array. Even if no data is lost the rebuild process will impact performance until it is done. Even a RAID doesn’t provide protection if the power is lost while data is being written, which could result in data loss.
Most Synology units used by homes and small businesses are four bays or less. These generally draw less power than a computer and a monitor so most UPSs targeted for computers can be used. Even 8 bay units can be handled by a low cost UPS. Rack-mounted or Synology units with more than 8 drive bays may require more research, depending on how much backup power you need.
Synology does list models that are known to be compatible in their compatibility listing. There’s a great degree of standardization among Uninterruptible Power Supplies, so unless you go really off-brand as long as your UPS can communicate to a computer via USB then it will probably work, even if it’s not on the list.
Disk Station Manager (DSM) also supports connecting to a UPS over the network. Since most UPSs only have one USB port to communicate this can be used to connect multiple Synology units to one UPS.
For example, I have several NASs connected to the same UPS. My always on Synology is connected via the USB cable. The others communicate to that UPS over the network. In order for this to work all the NASs and the network switch they connect to need to be in the same UPS. So you’ll need to be sure to have enough battery backup outlets in the UPS. Yes, you can split them across UPSs but that only works if the power fails to all UPSs at the same time and all the UPSs have enough backup power to stay up until all the shutdown signals are received. Not sharing the same UPS for power complicates network connectivity and makes it prone to error.
I use the CyberPower model CP1350PFCLCD UPS. It’s rated for 1350VA and 810W. One reason I picked it was that it has 5 outlets that have battery backup. This is enough to power the four Synology units I sometimes connect along with the network switch they connect to. If the estimates are to be believed it will power all for units, spinning a total of 16 drives for about 45 minutes. In other words, it’s more than enough power for almost any home or small business, yet costs about $175. Similar models, but with less reserve power are significantly less expensive. In most situations I’m running one Synology NAS with 8 drives so I get considerably more reserve power.
In my area, if I lose power for 10 minutes it’s a rare situation and probably means it will be out for ours. I set things to shut down after 10 minutes. This way if power is out for an extended period I have extra power to recharge a phone, tablet or a laptop for some extra power which is a nice little bonus.
Even though my utility power is reliable, I’ve been saved more than once by my UPS.