While most of what you speak of re Ceph is correct, I want to strongly disagree with your view of not filling up Ceph above 66%. It really depends on implementation details. If you have 10 nodes, yeah then maybe that's a good rule of thumb. But if you're running 100 or 1000 nodes, there's no reason to waste so much raw capacity.
With upmap and balancer it is very easy to run a Ceph cluster where every single node/disk is within 1-1.5% of the average raw utilization of the cluster. Yes, you need room for failures, but on a large cluster it doesn't require much.
80% is definitely achievable, 85% should be as well on larger clusters.
Also re scale, depending on how small we're talking of course, but I'd rather have a small Ceph cluster with 5-10 tiny nodes than a single Linux server with LVM if I care about uptime. It makes scheduled maintenances much easier, also a disk failure on a regular server means RAID group (or ZFS/btrfs?) rebuild. With Ceph, even at fairly modest scale you can have very fast recovery times.
Source, I've been running production workloads on Ceph at fortune-50 companies for more than a decade, and yes I'm biased towards Ceph.
With upmap and balancer it is very easy to run a Ceph cluster where every single node/disk is within 1-1.5% of the average raw utilization of the cluster. Yes, you need room for failures, but on a large cluster it doesn't require much.
80% is definitely achievable, 85% should be as well on larger clusters.
Also re scale, depending on how small we're talking of course, but I'd rather have a small Ceph cluster with 5-10 tiny nodes than a single Linux server with LVM if I care about uptime. It makes scheduled maintenances much easier, also a disk failure on a regular server means RAID group (or ZFS/btrfs?) rebuild. With Ceph, even at fairly modest scale you can have very fast recovery times.
Source, I've been running production workloads on Ceph at fortune-50 companies for more than a decade, and yes I'm biased towards Ceph.