I am currently running a FreeBSD system on an old Dell Optiplex 790 (i3 2100) that has been upgraded a bit.

It has 16G of ram, and 5 hard drives: 1TiB SATA SSD, where the OS itself is installed, using UFS+/FFS filesystem.

The other 4 are 3TiB SAS drives, connected to an LSI 9300 HBA, and are in a ZFS raidz1 configuration.

I would prefer to stick with FreeBSD, but would also consider TrueNAS Core (also FreeBSD based).

Here's the problem. The 5 hard drives don't quite fit into the case. The side panel won't close completely due to the SAS connectors being slightly larger than the original SATA connectors the case was designed for.

My budget is sub $300.

I've seen a few 2U and 4U servers on eBay that seem to fit the bill. My concern is that energy usage would be significantly higher than it is now.

Any suggestions for alternative ideas that keep my existing storage would be much appreciated.