Power outage risk with nvme r/w cache

Good day,
I have a DS923+, 3x Ironwolf 4TB (SHR1) + 2x WD Red SN700 500G nvme
How big is the chance that something will happen during a power outage if I have an SN700 as a read-write cache. Unfortunately, I only have surge protection. Not UPS.
Since the WD RED SN700 is not in the list of supported drives, Synology can’t help me with the problem. At the same time, SN700 does not have PLP like Synology drives
I’m not talking about the data just before the outage, but about irreversible damage to the storage. Is there any volume corruption protection in DSM7.1? Power outages are very rare in my area. Maximum 1x per year. Thank you.

Get a UPS, even a cheaper one that could power the Synology for 10 mins. Synology themselves recommend not to use a R/W SSD cache without a UPS as it can could a decent amount of damage to your data depending on what you do.

Just keep it as a Read only cache until you get a UPS.

Also, don’t skimp on the surge protector, double check how much your protector can handle and what the insurance is. I’ve a $60 surge protector connected to my UPS and if a surge damages any equipment connected to it, it’s insured for up to $20k.

I completely agree with @james-melb here: Go Read only!

I have had multiple cases where people have come to me with their volumes in ‘read only’ mode because of a power outage and a read / write SSD cache. The risks simply outweigh the benefit. A read only cache is really solid no brainier, and can’t corrupt your storage pool


Unless you have a UPS or a NVMe with Power Loss Protection (preferably both) you should NOT use a read/write cache - make it read only

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thank you a lot.
Btw your tutorials are best

ok, I ordered budget UPS - Eaton 5E 850i USB. Its in Synology Compatibility list (tested by Synology). :wink:

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I have a couple of nvme’s that feature dataloss protection but they come in the 22-110 size (intel dc series) and that makes them unusable in my synology for me but work in my truenas install. Luckily I have everything on a UPS.

Awesome. Any UPS will do. It having USB just means you can configure the Synology to auto-shutdown when the UPS hits a certain % of battery remaining.