Definitely. That's the whole point of even investing in a NAS in the first place isn't it. ?
Suppose the contrary,
IF after you have spent near to a $1K or even more for a capable NAS inclusive of harddisks which your expectation that you can put your data in there knowing it will be safe in it, but you decided to just take a gamble on the power supply, which is the most obvious criterion to reliability of an electrical appliance, knowing there are potential file or disk corruption or system failure in the event of a electrical surge or outrage, that doesn't seems like a sensible choice, isn't it
Consideration that it is a consumer class product used in a consumer scenario and therefore it doesn't require electrical protection compared to a multi-million dollar enterprise scenario seems rather unfitting in my opinion.
An enterprise loses reputation, loses customer confidence, loses credibility and definitely loses money and opportunity when your hardware or software fails. That is something we can all appreciate.
How about consumer, loses an entire collection of photographs of once in a life time honeymoon with your wife 10-30 years ago ? Can you get it back ? Loses the photograph of your parents taken 30 years ago, of your grannies, of someone you loved but no longer around, is it of less importance compared to the company losing data ?
How about the thesis that you have written 20 years back, that you know it is of importance to you, or perhaps an assignment you have just written 1 month ago, and you decided to place it into the NAS because you know it is a safe place to store your data. Does losing any of these information, or they are corrupted in some way which you never detect them, means less important to you as an individual compared to a company or a country ?
Redundancy is not backup. That is what some of us understand. However, when is the last time you went through all your photos or documents that you have saved in your NAS since 5-10 years ago, validate that they are still the way they are when stored into the NAS ?
Will backup solved the problem ? Think of this very common scenario, used in almost all backup strategy.
1) Store fresh data in NAS.
2) Periodically backup happens, maybe daily, weekly or monthly. Same data stored in another storage device
3) Retrieve the same piece of data, edit it and save back into the disk.
4) While saving, power outrage and the NAS just shutdown in the middle of the copy
5) Another period as past, backup from NAS into backup device
What happened ? Did the backup save your day ? If one is not even willing to invest in a UPS, I highly doubt one will be doing differential or incremental backup practised in an enterprise environment.
I know what some might say "Hey, you should have checked the data is written properly when the data is written". Sure one piece of data, no problem.
1000 piece of photos you are copy over from your host to the NAS, if you will check every single pieces after writing, sure. Good for you for you are a very diligent and cautious person. Do make sure you are regimental about it. That's part of the workflow to ensure data integrity. Otherwise no RAID or Backup is going to save your day
Bitrot, anyone heard before ? RAID write hole, anyone heard before ? How do you detect bit rot ? Technique read and write every single bits on the hard disk, that's why data scrubbing exist. RAID write hole ? Again data scrubbing, and even simple data scrubbing doesn't protect against, which is why with the introduction of BTRFS in Synology, it has file scrubbing to help in another level using checksum.
As you have mentioned, because you have placed all your data into one basket, and even most backup strategy employed are copy over without versioning, it is not as safe as one think it is.
Indeed how many times of power outrages do we experience in a year to be considered a good sample size to come to the conclusion the the NAS alone without any power outrage protection is a robust system ? Lets say 2 times of outrage per year, how about be prudent once every month ?
Is 3.28767123% is a good statistics to call out a system as been robust if it happens every month. What is the statistic of flipping a coin falling on its head ? 50%. High enough ? Can you be sure the next time you flip it will fall on its tail ? What is 3.28% compared to 50% as a reliable experience to brand a system without power outrage protection for most of us, power outrage are rare. In my experience, I have only encountered them almost once a year or even rarer. How many times will it take to corrupt the files in your NAS ?
Once. Which one it is will really depends on how lucky you are.
For me, I'm very lucky in a sense that my NAS has never broken down for 10 years, but in this forum and in fact in this thread, I keep seeing some people asking about where to RMA their faulty unit. Should I be complacent? I can definitely live for a month without my NAS if I need to RMA it, or I simply just buy a new unit to replace the current one. But will you be able to retrieve back a 5 year old piece of photo, corrupted 2 years ago without you know, overwritten again and again for the last 3 years into your backup ?
Well Good for you for you have chosen a path to better protect your data having the UPS is in my opinion, a significantly lesser cost compared to a SDG±1K solution.
For me, my data are uploaded daily to AWS S3 Deep Glacier with document versioning, because my thousands of RAW photos, especially my marriage, family photos/videos taken during tours are especially important to me, more so the older I get.
Personally I don't scrimp on such stuffs because I have the technical know how to make machines work for me, and if I measure the cost of losing my data to an undetectable situation, I would have invested in a solution that give me a piece of mind. Enterprise or Consumer is totally beside the point, because the perspective of COST is different.
Also as another poster have suggested, switch on your documents versioning on your NAS if such a feature is available. HyperBackup also support backup versioning, so use it if you can.
However so, the ultimate decision is the owner of his/her data. If you value your data, you know what to do. If you think you are adequately protected, good for you.
That's all I have to share.