6 Raspberry Pis, 6 SSDs on a Mini ITX Motherboard
Aside from running Ceph as my day job, I have a 9-node Ceph cluster on Rasberry Pi 4s at home that I've been running for a year now, and I'm slowly starting to move things away from ZFS to this cluster as my main storage.My setup is individual nodes, with 2.5" external HDDs (mostly SMR), so I actually get sligtly better performance than this cluster, and I'm using 4+2 erasure coding for the main data pool for CephFS.CephFS has so far been incredibly stable and all my Linux laptops reconnect to it after sleep with no issues (in this regard it's better than NFS).I like this setup a lot better now than ZFS, and I'm slowly starting to migrate away from ZFS, and now I'm even thinking of setting up a second Ceph cluster.  The best thing with Ceph is that I can do a maintenance on a node at any time and storage availability is never affected, with ZFS I've always dreaded any kind of upgrade, and any reboot requires an outage.  Plus with Ceph I can add just one disk at a time to the cluster and disks don't have to be the same size.  Also, I can move the physical nodes individually to a different part of my home, change switches and network cabling without an outage now.  It's a nice feeling.