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  1. Just a quick remark on PoE: You can see the different standards here (among other places):

    You should always buy a switch that adheres to the “802.3at” PoE standard (in the old days there was 24V passive PoE, but this is not used anymore).

    The Unifi switches have 802.3at PoE+ (type 2), which means it can power up to 25W at the endpoint. A cheaper switch might “only” have 802.3at PoE (type 1), which can power 13W at the endpoint.

    This can be a deciding factor when you decide how much should be powered from a single port. For reference, a Pi with PoE hat (and fan) takes around 5W.

    Type 3 and 4 are for enterprise use, and only available in really expensive hardware.

  2. First, are there limitations on POE as to what it can power…

    Great answer from @ameinild on that one. Thanks!

    Second, do you have to use identical hardware for all the nodes, and if not, will the slower hardware pull down the efficiency of the faster hardware?

    I have been doing more research and watching more videos on The YouTubes, but I am still unclear about the second part of this question. Let us say I have two Raspberry Pi 3 B+ boards with 2GB of RAM and four Pi 4 B boards with 4GB of RAM. Will using the Pi 3 boards as redundant controllers have an adverse effect on the cluster as a hole? My understanding is that the controller uses less resources than the nodes…which makes sense.

    …would it be possible to backup the entire cluster to Backblaze or a similar service?

    Still unclear on this

    …redundant controllers?

    Figured that one out…relatively.

    POE switches on ebay…

    I think I will use this one: TP-Link PoE switch

    …affordable UPS…

    IF I spend the money I think I will go with a small APC like the 700VA BR700G. I do not plan on plugging in anything other than the cluster, switch, router and modem.

  3. So the smokeping example in this video shows the data for that program as stored on the node that is running smokeping. Is it possible that pod could be started on a different node if say the cluster were shut down and restarted? Or if the pod were destroyed and recreated? If that were to happen would the data be transferred to the new node? Or would the persistent data only exist on that original node? Is it possible that the persistent data could be lost for that pod? Could/should the data be stored on an external data server? If so how would that be set up?

  4. I am not sure of the answer, but my minimal understanding of the topic thus far is that persistent storage is a sore spot of sorts for k8s. If/when I get my cluster up I am going to look into Longhorn. Covered (somewhat confusingly for beginners) by Techno Tim here on The YouTubes.

  5. Patrick at Serve the Home has a ton of reviews of the ThinkCentre and other “tiny mini micro” format PCs…

    Exactly where I got the idea :slight_smile: I have been looking on eBay, but have not found a superb deal yet. The advantage of the BEMAX is what you said about power/heat…at least compared to the Tiny PC options.

    I saw you mentioned UPS; we use CyberPower ones…

    Good to know!

    Windows licenses…[are] tied to the hardware…

    Shoot

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