Recently our local substation had a catastrophic failure that led to an unexpected power outage. It happened early in the morning and even though I was home I had no chance to shut down any of my servers cleanly. The power cut out and back suddenly 5 times in less than a minute before finally there was no power. I cannot fault the power company as soon as I reported the fault I was constantly updated on their progress and power was restored within 3 hours.
However, while I waited for power to return, I was worried if any of my IT equipment had suffered any damage when the power was cutting in and out. I have a small lab for my business that consists of a Synology DS918+ NAS, HP N54L, Dell T20 all running 24/7. Any issues with the two servers would be inconvenient but I could recover as I use these for testing, no critical data or services are stored. The NAS was purchased as my local backup and was meant to be the first line of defence against data loss to either of the two servers or the laptops and desktop!
I backup all my important data to the cloud but I would like to be able to restore easily and quickly from a local backup. Fortunately, everything survived, no data was lost. Getting a UPS has been in the back of my mind for a while (years) but other purchases always took priority. This incident motivated me to actually go and get a UPS.
Which UPS?
It is not easy to decide which UPS to get, I do not mind admitting I had no clue what to look for. I came across a helpful guide on the NAS Compares site. Even after reading the informative article I was still not 100% sure if I could pick the right UPS. I asked for help from SPAN and Paywand emailed back recommending the APC SMT750I or for headroom the SMT1000. I kept reading various forums and articles on how to correctly size a UPS. During my research I realised that at the price point I was looking at the UPS would be able to power multiple devices but only notify one of them when power was lost/battery was low via a USB connection. I needed all my devices to be shutdown gracefully, not keep running until the UPS ran out of power.
The DS918+ has a package call NUT installed that can act as a networked central management point for a USB connected UPS. This means the UPS would be connected to the Synology via USB, the default config supplied by Synology sets it up as the master. The other servers would need NUT installed and setup as slaves. When the UPS sends a signal to the Synology to shut down, the NAS can retransmit that signal to any configured slaves and they too would shut down. The alternative is to purchase an expensive management card that allows the UPS to be managed via ethernet.
Requirements
After initially, incorrectly, assuming I only needed the UPS to power the NAS and two servers I now realised for the NAS to be able to communicate with the servers during a power outage I would need the RaspberryPi (DNS server) and the network switch connecting all the devices. The SMT1000 would probably cope with these additional devices but I wanted additional headroom in case the power draw from any of the servers increased because I added additional hardware or more likely I decided to add more devices to the Lab. Lots more reading later and I finally settled on ordering the APC SMT1500IC.
Network UPS Tool (NUT)
I'll discuss my setup and installation/configuration journey with NUT in my next post.
