All hardwired, all plugged into Audioquest Niagra 1200 power conditioners.
I’ll turn it on, it will boot up, then Roon will rescan the drives, and all the files will show up, then <12h later the NAS has shut itself off and I get to go from scratch. I went to the NAS GUI and updated the firmware, to remove that from the equation. Do you think this is a power grid fluctuation and that the power conditioners are hindering not helping?
My DS216+II with 3TB WD Red drives stays up until I power it off with all other gear when I’m away for extended periods. No power conditioners for the NAS or other computers, just good but basic surge protectors. OTOH, an earlier Synology NAS (DS214???) that I gave to my daughter started failing intermittently and eventually died totally, out of warranty. Periodic computer/NAS crashes are sometimes associated to bad DRAM: as the machine runs and allocates more DRAM for data structures and buffers, it eventually touches the bad memory locations and the whole house of cards comes crashing down. After restart, it again takes a while to bump into the same bad memory. Rinse and repeat.
Also check temps. I have a QNAP, but had the random shut down problem. Fan was on auto. I changed to run fan continuously at low speed and problem went away.
First thing to do is disable the automatic backups. They take a LOT of memory. I had this trouble with a DS716+ NAS which is exandable only to 2GB RAM. Check your RAM usage. I had dropouts with RAM issues reaching more than 90%. Since then, I spoilt myself and upgraded to 1821+ with 64 GB RAM! No issues anymore with the RAM usage. And no, you don’t need 64GB! But certainly advisable to get at least 8 if possible. I forgot to mention that I have 60,000 tracks and that makes a difference to the RAM usage when backing up.