Data centres, business, hospitals etc. run batteries to bridge the gap until the diesel starts running. It can take a minute or a few until the diesel generator takes over, but it can run for hours and days with refuelling.

Getting batteries for 8h is expensive and risky - what if the power cut suddenly lasts 9h? With batteries you have a fixed storage, with petrol or diesel you can just refuel.

Having that unreliable electricity, my home server would be the least of my problems. I would already have a generator to keep the fridge running so the food doesn’t go bad every other day.

You should get/use one external drive for backups that you store separately (can be your 2nd or a new one). Having two separate internal drives for backup is not safe, as the system can damage data on both at the same time (e.g. malware/encryption, data corruption etc.).

RAID is for availability/uptime. I like to compare it to a shop system at the checkout. You can’t have shop payments halted if one drive fails, so you have a RAID. It allows you to repair/replace while the system keeps running and your business keeps operating. In a large business, every hour of downtime can cost you hundreds of thousand of currency, so RAID gets even more sophisticated. Downtime is not an option.

At home this is up to you. RAID can save you some hassle and grant performance, but likely costs you more money than it saves you. Backup is key, so have at least one separately stored copy and depending on the importance of your data, also have an off-site backup.

Hm I have not heard about such an issue so far but I also don’t have as many UPS as you.

I see you holding a red cable which could be +. When I switch UPS batteries, I do it the same way as it’s recommended for car batteries to avoid sparks/arcs. Remove - (black) first, as it won’t spark/arc. Then remove + (red) as it can’t get a circuit closed any more, so also no spark/arc.

When plugging a car battery in, it’s the other way around. + (red) goes in first and only then you connect - (black) to avoid spark/arc for both connectors again that way.

I’m quite disappointed by most comments so far talking about RAID and data loss. That is not what RAID is for at all.

RAID is for uptime/availability. When a drive fails, the system will keep running and working. For companies, that would lose thousands of currency per hour with a downtime, this is super important that the system keeps running. At home, it’s convenience that you can order a new drive and replace without hours of setting up and copying before you can watch the next episode again.

Backups are against data loss. If a single drive fails, a RAID fails or you get some encryption malware or an employee destroys stuff on purpose, then everything is destroyed. It doesn’t matter if it was a single, any RAID, HDD or SSD. You order a new drive, make a new volume and restore the data from your backup.

You can add drives later and you can also change the RAID type later when adding a drive.

Online RAID Level Migration supports the following RAID migrations:

Single drive to RAID 1

RAID 1 to RAID 5

RAID 5 to RAID 6

But you can only migrate to a different RAID within that scheme when adding 1 drive, as the new drive will be used to create that new RAID level. Changing the RAID type otherwise will require making every fresh and all data will be removed.

QNAP HowTo: https://www.qnap.com/en/how-to/tutorial/article/online-raid-level-migration

Hm but that adds a lot more complexity, as then every single network item has to have an UPS as well, right? Certainly not a problem for a company with server room and racks. But at home in a house, the hardware might be spread out across rooms and floors. If there is a switch somewhere without UPS, it will cut off certain clients from receiving the signal via network upon power outage.

Is this doable with one UPS? I’m thinking of the signal wire so the device knows it’s running on battery and has to shut itself down sooner or later. We have 2 (who need shutdown, +1 can just lose power I guess) different devices mentioned here.

I have one older APC UPS on the PC and one newer Eaton UPS on the NAS. Each UPS has a signal port with a cable connected to the main device that runs some software to notice when it’s on battery and supposed to shut itself down after X minutes battery time.

The NAS UPS also has the router, phone and zigbee hub connected, but only the NAS will shut itself down, the rest will just lose power at some point, but those don’t matter.

How do you get the server and NAS to both get the signal and both shut down after X minutes? Is there a specific UPS features required?