Good.
All large 2.5" are SMR. Given you have three of them, there’s a chance that they can be made to work as an aggregate with decent speeds by spreading I/O over all three of them, leveraging the max-concurrent-requests option, and putting database files that keep accounting information on non-SMR storage (they’re very small). There were some threads on configuring Storj nodes on SMR drives here, but I cannot quickly find any authoritative post on the matter. Community, can you help?
Though, I wonder why %util doesn’t show the problem then. Was it measured freshly after a restart?
Interesting! Proxmox used to not handle NUMA properly, ie. matching physical sockets to virtual VM sockets, leading to the NUMA option basically slowing down everything without purpose. If they do so now, great!