I've been hunting for a multi-drive eSATA enclosure for use in backing up my Mythtv box.
Today I belatedly discovered the MediaSonic brand -- they make some really nice enclosures. The one I picked up today for $90 is the
HF2-SU2S2, which is a 4-bay eSATA/USB2 enclosure, with built-in SATA port-multiplier.
No built-in firmware RAID or other features in this one, just a simple holder for up to four SATA drives of any capacities. One eSATA cable connects the four drives to any of the eSATA computers I have around the office, and it all works rather swimmingly with Linux.
It's very small, with great cooling -- thermostat controlled fan with manual overrides. The fan is quiet, except for a slight rattle on the lowest speed. All four drive bays are hot-swappable of course, and the port-multipler chip (JMB321) supports SATA NCQ via FIS-based switching, which works with the JMicron eSATA ports on all of the mobos I have here.
They also make a USB3/eSATA version of the same enclosure, the
HF2-SU3S2, but I preferred to save $30 and gave that one a pass for now. Next time.
Plug something like this into a Zotac ZBOX nano or mini-itx system and roll your own NAS with Linux. There are also larger 8-bay units, and fancy-firmware versions of them all for Windows users.
Cheers