How many projects does it make sense to combine into one Pi?

[gribensk]

Hi all,

So I recently got a couple of new raspberry pi's, and I was wondering if I should consolidate projects. My question is, how many projects does it make sense to combine into ONE pi. So far I have a Pi that is both a headless seedbox (transmission) along with an SMB server. And I have another pi that has PiHole installed to filter out ads, along with being a VPN using PiVPN (OpenVPN) so I can access my home network remotely. I was also thinking about running some media program like Kodi off of one of them. So does it make sense to keep these on separate Pi's or should I just combine them into one and save some energy and a few cables? One is an Rpi 3b+ and another is an Rpi4 with 4gb ram.

Thanks in advance.

[Heater]

What CPU load would all your applications have? In your use case?

What amount of storage would you require?

What network bandwidth do you think you will need?

When you can answer those questions you will know how many projects does it make sense to combine into one Pi

We cannot judge this for you.

[gribensk]

Hi Heater,

Thanks for the reply. In answer to your questions, I think the projects listed that would be a large CPU load would be the VPN and torrenting, which together would be for very short times (less than an hour a day). I have a 2TB SSD drive mounted, so I don't think storage would be an issue, and I only have 200 mbps internet, which I assume one Rpi can handle regardless. Does that change your answer?

[rpdom]

From the Raspberry Pi Trading Ltd view - the more Pi the better (as all profits go to fund the charitable aims of the Foundation).

In practice you can run many projects on a Pi at once. I have a PI 2B that is a DNS and DCHP server (using DNSMasq), a Database server (MySQL), a Webserver (Apache), A File server (NFS and SAMBA), a Time server (ntpd), a local mailserver and a few others.

I also have a Pi 1B+ that handles my VPN traffic with no problems. The Pi 2B could probably handle that too.

For 200Mb/s internet you would need to use a PI 3B+ or Pi 4B. The earlier models are limited by their 100Mb/s ethernet interfaces although you could get a USB Gigabit ethernet interface. To use USB storage at the same time, a Pi 4B definitely has the advantage as the 1Gb ethernet interface is one a different bus to the USB interfaces.

[hippy]

I would tend to favour 'one Pi per major function', so I would have separate PiHole, Kodi and NAS Pi's for example.

That way one doesn't need to worry about any function adversely affecting another and one can pull a function from the whole without affecting the others. If something breaks or fails, experimenting, upgrading, or whatever is being done, goes badly wrong, you only need to reinstall and set up its functionality, not anything else. Better to lose one thing than everything.

It also means that when upgrading an OS - as will happen from time to time - one can do things individually and at leisure. It's no longer a case of having to upgrade and get everything working again before being back where you were. That's better if it's not as straight forward as hoped for.

[LTolledo]

Same with hippy, one main task per board, with a small few with secondary (and even smaller few, with tertiary) functions.

modular systems design makes for easy maintenance and troubleshooting, and easy to make redundant/backup systems as well.

if all functions are forcibly crammed into one system board, and if ever that one system fails..... all fails...
.... and somebody might loose more hair (an perhaps sanity as well) faster than humanely possible

[gribensk]

That's great advice and makes total sense. Having screwed up multiple pi's, I think I'll keep the projects separate. Thanks, all!

[Raspberry Paul]

I develop and test on separate Pi's then combine on to a "Central" pi if possible.. Only reason I have separate Pi's is needing to use the same GPIO for multiple projects.

Following this Andreas Spiess youtube I now use Docker to separate the "server" stuff on to one Pi.
https://www.youtube.com/watch?v=a6mjt8tWUws

Originally built on a 4gb Pi4 but now running on a 3b+ without issue.