I've setup OMV 5 using a Rock PI 4B with 4 gig ram.
I have Penta SATA hat in the Radxa case Currently with a 2TB SSD soon to add 1 to 2 more. The Rockpi allows PCI vs USB connectivity to the disks.
I am using as a file server on my home network as well as a server for my music collection of about 3000 albums encoded to flac files-.
Currently I have Plex server installed and this is working fine as a media server but am not sure I will use long term. My old system was Slimserver and still evaluating alternatives for
Performance has been very good with around 80Mb/s file transfer rate which is just about maxing out the 1Gb Ethernet connection.
The CPU is not being taxed even with transfer rate through the Ethernet connection maxed out.