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hello
It has been strongly recommended that I buy a UPS (in addition to the £1,000 I have paid for the 923+ and HDD :/ ) ... There are literally thousands online ... I don't want one like a PC tower which most are. I have found an Eaton3S 550B - 3s550b , which has a USB to connect to the NAS ... I am struggling to find out if it will work ... any thoughts ?
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I recently watched your excellent review of UPS units in regard to protecting your NAS and choosing the appropriate UPS unit for your use case:
UPS for Your Synology or QNAP NAS - 8 Things You Need to Know & Recommend UPS' to Buy
After recently suffering a RAID failure (not on the NAS) I began to investigate the failed system and quickly realized that the involved systems did not have a means to detect the UPS running on battery and perform graceful shutdowns. One of the connected devices was indeed a Synology DS918+ unit that did not suffer a failure although that was likely more luck than anything. I have since set up the Synology as a NUT server so that it at least goes into safe mode after some time when running on battery to prevent damage.
IMHO, all NAS owners should understand that they should have a strategy in place to dealing with a utility power failure if the device is not being shut down on a schedule, or in the event you allow a NAS to run overnight, or these devices are running at a remote location like an office or satellite office with a backup NAS.
One of the main issues alluded to in your video was the connection of ancillary devices that are connected to your UPS and are drawing power during a utility power failure. In my home setup, I am powering a cable modem that is my television and telephone, a Wifi router, emergency weather radio, etc, along with my Synology unit, and perhaps a PC (if I forget to shut it down before bed). With everything connected, I have about a 15 minute window to shut down the PC and Synology. The rest of the units should have no problem with abrupt power loss.
The interesting part for all NAS users is what happens when you deplete the battery, the devices are all cut off, then power returns later with an auto-restart on utility power restoration that many modern UPS units have. If your UPS powers up, with depleted batteries, you are operating your NAS in the 'danger zone', in that a subsequent power failure that may occur before your batteries are sufficiently charged, could lead to yanking the power of your NAS while it is writing to the RAID drives. One can only imagine the consequences of a failed RAID on a Synology unit where the built-in repair utilities may not be able to fix the RAID, but I digress.
I have laid out the details of this problem with the Synology units as they do not by default shut down. They wait in standby for a return of the power by monitoring the UPS while running on battery. In essence, the Synology itself becomes a parasitic power draw during extended power outages.
If the power returns while the Synology is in standby, it reboot and recover. If the utility power does not return before battery depletion, and the UPS auto-restarts, you have entered the 'danger zone'. There is a hack that you can do on the Synology units by modifying the internal files via a terminal that will cause a shutdown rather than a standby but you may lose these changes on a DSM update and you will not be able to auto-recover the Synology at a remote location upon the return of utility power (as I understand it).
While buying a $1500USD unit that offers a 'battery reserve' can solve this problem however most (if not all) consumer-grade UPS units generally do not have that feature.
The bottom line for me is that if you have an auto-restart UPS that does not have the battery reserve feature, and a connected Synology that will auto-start on the return of power, you are entering the 'danger zone' if the UPS starts up under sketchy utility power after an extended power failure with depleted batteries.
It would be great if you guys could do another video addressing graceful shutdowns and the various options like NUT clients (built in to the Synology units).
Thanks for the great videos.
