I’m using A Raspberry Pi4 as a dedicated Timemachine backup server with an SSD via USB3. Works perfectly for a year or so.

However that requires the disk used for backup storage to also be always on.

Disk have power modes and can be spun down to save energy. A Raspberry Pi can run the OS on an SD card and mount the disk for backup storage. Leaving it in low power for a long period of time.

I'm worried about the wear on my drives spinning up and down so much? Maybe it isn't such a big deal. It is the most stressful time for spinning drives, though.

I use my pi as a backup server. The disks spin down when not in use.

Ideally I would like the "wake-up / fake on" infrastructure to be a feature of my wifi router.

I wonder if you could build this as a plugin for opnsense.

i run an rpi to host stuff for cheap (the energy drain of the pi is low), my main machine goes to sleep after 15min to save costs. seemes like a neat trick to remotely wake it up

I agree, but you could argue that the Raspberry Pi is not performant enough during restores or browsing the backups. During the backup itself performance should not have to be that big of an issue as it's mostly a background operation you will not be waiting on.

You could also use the RPi as a stepping stone which syncs it's files to the 'real' backup server which is on a daily/weekly timer instead of on-demand setup.

I'm using this concept for the problem that I want to collect metrics all day long, but not have a power hungry server running 24/7. So my RPi collects all metrics and streams then directly to my server for me to view realtime. But whenever the server is unavailable (on schedule or for maintenance) the RPi just buffers the metrics until the server is available again.

Also worth considering is just not using a single server for a single purpose but just cramming it full with utility to justify the power costs.

Then how about an N95/N100 (recent Celeron successor) mini PC, like the ones from Beelink? They don’t draw that much power, but are 2-3x faster than a Raspi, have HW supported video de/encoding and can even run Windows if you needed that.

"that much power" is pretty subjective, is it 2x or 10x a pi? Might be a turnoff for some.

The N100 has a TDP of 6W. I haven't measured power draw of the whole system yet though, I imagine that the mainboard will pull another couple watts at least.

It shines especially in scenarios where the Pi is just a tad too slow. E.g. you can't live transcode 4k videos on a Pi, while the N100 has latest UHD graphics and therefore ships with a decent HW-accelerated H265 en/decoder.

There are a lot of low power media boxes but few servers sadly.

By server i mean multiple network ports and storage ports, space in the case for several spinny discs in addition to the ssds etc.

I doubt any NUC is good for a server by my definition.

Sure there are, there are lots of NAS appliances boxes from the likes of Synology/QNAP/Aliexpress Special that can run double duty as servers built on similar low power CPUs. Some of them even have decent networking options.

The problem is that a lot of the commercial products are woefully underspecc'ed for the price and you outgrow them quickly. Spinning disks also eat a lot of power, relatively speaking, so they kind of eat into the "low power" usecase.

> lots of NAS appliances boxes

Rather roll my own Linux thank you.

> Some of them even have decent networking options.

I think few of them have multiple ethernet ports. Plus there's the matter of how much cpu the built in ethernet eats.

> Rather roll my own Linux thank you.

Most modern NAS have that option. It just doesn’t make that much sense since that would get rid of the (in some cases really good) DSM.

It does if you want more than a storage appliance. I want the option of setting up any linux server software on it if i feel the need. Just a general purpose low power computer.

You should actually look at what's available. You can get a QNAP box with an ARM CPU with lots of drive slots, dual 2.5 gig Ethernet and dual 10 gig SFP+ for like $700, among many more examples. Sure saturating those is gonna eat a ton of cycles and run like shit but... yeah of course it is it's a cheap low power CPU. They suck for the sorts of stuff I wanna do, but this is inherently a market segment that involves compromise and that is probably perfect for some people.

I agree I'd much rather roll my own system (and that's what I did) and I would personally never buy one of those, but it's simply not right to say there are no options available if you want a low power server off the shelf. Some of them are even decent if you wanna pay for it.

Have you seen the board talked about on this thread?

https://forums.servethehome.com/index.php?threads/topton-nas...

There is a newer board with a J6413/6412 that could also be a candidate if don’t need quite as much processing power.

Reports are that servers with this run under 10W at idle.

Hmm I don't think I dare. But thanks.

> power hungry server running 24/7

Nothing in this article supports this statement. It just says "high power consumption" without measuring, and declares victory without measuring the power saved. The fact is that power scaling has almost erased the difference between "suspended" and just "idle", to such an extent that there might not even be a meaningful difference, or any measurable difference.

My NUC 12 Pro is drawing, at the wall, 2.7W, as best as I can measure. The SoC reports drawing below 200mW. This server is on. The way to get low power states on these is to just make sure your Linux is up to the task and your BIOS works correctly, which is one of the reasons to choose a NUC. The first-party firmware works!

Another important thing for low-power server operation is to either use wifi, or make sure your ethernet is configured correctly for low-power operation. Unless you fix it, gigabit ethernet by default will propagate the link state all the way down to a high power state on the CPU. The NIC will say that it has tight latency requirements because the link is active, and it will configure the PCIe bus to avoid PCI link power management, and it will tell the CPU that it can't go below PC6. To avoid this you have to configure your NIC to ignore link latency requirements. Just unplugging the ethernet is the easier path, and it's faster than gigabit these days.

NOte that the NUCs with power saving and wifi have a serious problem: latency. By default in the various Linux OSen I use, wifi power management is enabled. Often times, repeated pings will jump from 5ms to 100+ms (with a very high variance) and network bandwidth will be extremely poor. Even ssh on a LAN can be unusable!

Sure, but it's a miracle that it can do this at all. It's entering and exiting a sleep state that is very nearly off, in between pings.

My first thought too. Reports can show the power usage for each process. So reduce the power-hungry processes. Or schedule them for lower cost times of day.

Full-size systems often have horrendous power consumption at idle.

Here are some pulling 80W at idle: https://www.anandtech.com/show/17548/the-msi-mpg-z690-carbon...

Here's a threadripper rack server pulling 140W (!!!) at idle: https://www.servethehome.com/asrock-rack-trx40d8-2n2t-review...

Meh, I struggled to get my pi to work as a time machine server. It would work for a few weeks and then just stop working and I would have to start the backup from scratch previous backups becoming unusable.

In the end I just plugged an external hard disk into the mac.

I have had similar issues in the past even with such simple things as SSH to a Mac. It would be easy to blame the pi or Linux, but as far as I can tell, Apple just does not play nicely with anything not Apple. It's just that little bit different. I have no such problems interfacing Linux and the pi with anything else.

Time Machine over NAS has always been unstable for me. As you experienced, my backup would be regularly corrupted and would need to restart. Alternatively, a normal <10G backup could take in excess of 24h.

I eventually gave up on the NAS and now backup to external drives at home.

This site has excellent articles on Time Machine - scroll down to Time Machine Problems: https://eclecticlight.co/mac-troubleshooting-summary/

I had the exact same problem and ended up with the same solution. I know people who have had somewhat better experiences backing up to something like a Synology, but the $Xk investment wasn't worth it for me without also needing it for big file storage or media serving or whatever.

> backing up to something like a Synology

How about QNAP? I happen to have one gathering dust, if you can reliably Time Machine to it i'd plug it in.

There are some quirks to setting up SMB so Time Machine is happy, but I have had great success with ZFS+SMB hosting my TM backups. Have been running for a little over a month and nothing is corrupt. Self hosting is still somewhat hard, I don't blame you for bailing on something so critical to uptime in the first place.

My time machine share is backed by ZFS. I have a separate dataset for each laptop, with snapshots retained for 30 days. As long as I know roughly the last time the backup worked, I can restore that snapshot so I don't need to start fresh.

I had the same - ZFS across four drives with separate dataset and samba shares for each machine in my house. It would work and yes, I could rollback to a working snapshot. But it wasn't a set and forget system.

Time Machine has improved a lot after the switch to APFS. Mostly because it supports full snapshots, with an easy way to get the difference between two snapshots.

The previous HFS+ version relied on directory hardlinks that were notoriously buggy and easy to corrupt. The difference computation also required basically recursively walking the entire tree and comparing the directory change times, with each lookup requiring a network round-trip.

You could run avahi and 'a simple ruby script' on the router instead (ok not most retail routers as stock, but e.g. OpenWRT) and do away with the Pi.

Nice to know I'm not alone. If I could reclaim time spent on rabbit hole projects that concluded with bail out, I feel I'd have a whole other lifetime. Yet somehow, each new rabbit hole project lures me in.

If an idling raspberry pi is too power hungry, a microcontroller like an ESP32 could be made to respond to ARPs. $8 for the MCU and a couple of afternoons of noodling. It's not going to run avahi for you though.

Use a beaglebone black. modern rpis use too much power.

You could have an Arduino to wake the Pi.

You can't sleep a Pi.

But then, why not just use an ESP32 which can replace the Pi entirely in the proposed setup. ;-)

I would have an ESP32 impersonate the MAC address of the server passively (ie. only in the Wi-Fi association), then “push the wake button” if it found traffic that is allowed to wake the server. A wake-up firewall, if you will.

Or a "smart plug"

That's what I was thinking too. My home server consumes like 15 W and is silent (and saturates gigabit).

If you get a rack mounted server made for data centers and stick it in a closet so you can't hear it then yes, i guess this approach makes sense.

> and stick it in a closet

went down that route years and years ago and... it heats up the closet.

Actually, (though not a server) I remember one place I lived, I just put my monitor, keyboard and mouse in the bedroom at a nice desk. Then I ran the cables through the wall to the computer in the next room where it could be loud and cool. (quiet, fast, cool: pick two)

Haha when I was young and didn't know better i splurged on a dual socket AMD desktop. Athlon 1600M it was, I think.

Ended up physically removing a CPU because the noise and heat was... not... worth... it.

> This looks like one of those home server infrastructure setup rabbit holes I would've bailed out of within the first 10 minutes of Googling to research the problem.

Absolutely have felt the same often, in the past. Good news! There's ChatGPT now!

It's so much quicker than google for figuring out approaches; it's great for explaining concepts and "how to do x with tech". And it's great at writing the scripts for you too. I set up a prometheus/grafana dashboard with scripts for various temperatures from various APIs with its help.

Not trying to shill, but just sharing that this type of project is something that's a lot more feasible to implement in limited timeframes than it used to be. (and get the satisfaction of bringing the idea to fruition)

But I reckon I'll always want content like this that covers the journey of uncovering various edge-cases, too...

This seems like an example of the worst setup for ChatGPT.

There isn't much info on the internet about it. Of the info that exists most is inconsistent, outdated, and/or wrong. The specific instructions need to depend on what's supported by the exact model number of your network card. You're dealing with hardware, so there's a chance of breaking things permanently. Close has zero value, the solution needs to be exactly right. Close but incorrect solutions are hard to debug.

I didn't in-depth read the main article here. But skimmed most of it.

Not sure any of it is going to brick hardware, but I haven't played with setting flags with ethtool. I've messed with Wake-on-Lan stuff in the past, as well as "prevent device from randomly waking from sleep" issues, too (on Windows, though).

I do have the advantage of a lot of past experience with Atmegas then RPis, so know a lot of the common sense hardware considerations... and a lot of troubleshooting. For me getting 90% correct with ChatGPT, and building up incrementally, has been an improvement on doing it all myself with google.

I might take an attempt at asking chatGPT how to do what the author did. Could be informative, even if just introspective realizations like, "oh, this is a question I asked in a good way due to my existing knowledge."

So far my experience has been the opposite with ChapGPT FWIW. Overall it has cost me more time sending me down rabbit holes that it totally made up, but said with absolute confidence.

This is interesting to hear!

A key caveat in much of what I'm doing, is I'm implementing things I previously did for other projects in the past 15 years... so I'm using old technology, know the terminology, and can troubleshoot 90% correct stuff that chatGPT gives me.

I haven't done as much "I have no idea where to start" stuff.

I have, and while it’s not perfect I’ve found that it makes a great tutor. I’ve asked it a lot of programming questions where my starting point was 0, and my biggest takeaway is it will give you exactly what you ask for and nothing else.

This can be a bit of a problem since you can’t ask for what you don’t know, so starting broad by having it explain the general concepts to you, and then slowly getting more specific with direct pointed questions had the best outcomes.

I came at it too from a 'I've done this for more than a decade' perspective as well. I simply found that it's advice was already something I knew, or outright wrong, or wrong but very convincing that it could work.

ChatGPT can't even do sensible NGINX configs, despite feeding it documentation. Gets URL rewrites wrong et al, hallucinates things that aren't even there. Troubleshooting its output is more labour-intensive than just doing it right in the first place, but most folks' Dunning-Kruger complex prevents them from knowing when the output is wrong in the first place.

I had a somewhat similar setup and it worked pretty good as long as I needed it. A Raspi, which would also do other stuff, like provide the DNS service, would wake up a backup server, which was a Xeon machine and consumed a lot of power, also was running Windows. The Raspi would wake it up 4 times a day, the server had a Task set up to run some Python scripts which invoked robocopy so that the server pulled the data off of another machine which was always on and required to be backed up. When ready it shut itself down and all was good.

Personally I like having courage to try. I don't tend to see things as requiring maintenance. This looks like an afternoon of messing around and should just work. I don't expect troubleshooting to be hard.

I really love people who can show courage & interest. I feel like computing has decayed into vapid consumerism. Products no longer even try to be semi-technical. There's a whole culture built around telling & selling ourselves the idea that computers are hard & difficult.

All it takes is one person with a good blog post to demystify & make accessible. You are smart enough. You can be that person. You can Augment Human Intellect by talking through it.

> A Raspberry Pi that itself would work just as fine as the Time Machine server the author seems to need on demand?

A Raspberry Pi has one big problem: no SATA ports.

Yes but RPI 4 has usb 3.0 ports that you'd really struggle to saturate with a gigabit connection - I used to see the lack of sata as a major problem with that platform but nowadays it really doesn't matter.

AFAIK the USB ports on RPi are shared with other peripherals. And there is no way you can connect more than 2 SATA drives without additional HW .

On Rpi 4 the USB 3.0 ports get their own dedicated USB 3.0 controller that's connected through a PCIe 3.0 1x bus. They don't share bandwidth with anything else.

OTOH, there's a ton to learn going down rabbit holes, and these are the reason why I stick to Linux.

I think it’s not too bad. Of course, I knew most of the ingredients before reading this article. I think my Router OS router can also do the ARP thing.

> Especially since the setup requires a Raspberry Pi to run permanently.

Which they'll gladly do no?

If (poor quality) SD card corruption is a concern, you can have the RPi mount the SD card read-only or just keep a full backup of the SD card.

I've had a RPi 1 power 4 VoIP Cisco phones for years. Zero issue.

I've got another one constantly establishing a remote SSH-tunnel so that I can easily troubleshoot my brother, who lives in another country, 's LAN. The uptime is more than a year.

One is routing (well, doing SNAT really) and firewalling between two non routable LANs. I set up the thing once and it's so reliable there's neither a screen nor a monitor hooked to it: just the power adapter and two ethernet cables (including one in a USB-to-ethernet adapter).

Another one is running unbound. Same: no monitor, no keyboard, no nothing. The power adapter and one ethernet cable. Simple. Not much can go wrong. No moving parts. It's happily null routing hundreds of thousands of crappy domain names 24/7.

I've got another one in a vintage arcade cab with a Pi2JAMMA adapter. In years it never failed to boot once. As we the others, just in case, I still have a "dd" of the entire SD card. Should something happen I'd just dd the image to a new SD card.

The shortage of RPi is apparently due to companies snapping them all for industrial uses.

I haven't heard of many people complaining "my RPi died overnight" (unlike, say, the Apple M1 laptop's screens).

They're incredibly reliable pieces of equipment for their gentle price. In case something goes wrong on one of mine, I just have a dump of the entire SD card.

I don't disagree that they may be a pain in the butt to set up, just like any server. But once setup, they don't move under your feet so the maintenance is really minimal.

I hate that there's a shortage of Pi but I'm not sure that criticizing them as "non reliable" is a criticism made in good faith.

I'm not sure OP was necessarily implying that the Pi specifically wasn't suitable for the job -- perhaps just that requiring /any/ other additional computer to achieve this is not without additional administrative overhead and power costs.

It does seems likely that a Pi is going to consume a fair bit less energy than the x86 SFF PC, so it's probably a net gain there, but that admin overhead thing isn't necessarily one to ignore -- it's not entirely set and forget.

Man I loved my RPi remote SSH-tunnel for being able to access my home network from anywhere... until my kid needed a Pi for a robot he got for Christmas and I decided to donate mine to the cause :)

That's exactly the right excuse to buy yourself a second hand mini PC and install proxmox / tailscale on it ; )

My solution to the "10 years old PC used as a backup target" was to just donate/sell-off-as-parts the old PC, and replace with a 10 year old laptop, with an external USB enclosure. From 180-200 Watts down to 10-25, but it was not as much fun with two weeks of a rabbit whole digging :)