Design and features
Thecus has carved quite the name for itself amongst network storage enthusiasts; however, of late it's faced stiff competition from the likes of QNAP and Synology, which offered similar performance and features, but with a much nicer looking chassis and interface. To this end, Thecus has released a new look firmware for its NAS, which is now rather AJAX heavy just like its competitors. The result is the inevitable increase in lagginess of the interface, but as a trade off the ease of use is significantly higher.
A five-bay NAS, the N5500 straddles the prosumer to SMB category. This in particular is highlighted by the presence of two Disk On Module (DOM) units, one containing the operating system, the second a mirror of the first, adding some redundancy for more demanding environments. There's still the power supply as a single point of failure, or potentially even the motherboard, but doing anything about that would likely drive costs up substantially.
Of course the usual iSCSI support is there too, and through USB it can act as a DAS too, offering a fairly large degree of flexibility. You can even choose the file system, a welcome addition, either going with EXT3, XFS or ZFS, although the latter would have to be run in user space to avoid licence issues, meaning performance wouldn't be too great. Not to mention it's there as a file system only — RAID-Z is not offered on the N5500, leaving the user with the choice of RAID 0, 1, 5, 6 or JBOD (and whether or not to encrypt those volumes). If you run out of space, you can stack multiple N5500s together using iSCSI to make it appear as a single storage unit to the outside world.
The dual-gigabit Ethernet ports support 802.3ad link aggregation, although as usual with Thecus we had fun navigating through it's not-so-intuitive LCD screen to manually set an IP to begin with — for some reason Thecus chooses to ship with DHCP disabled, a practice we wish it'd reverse. In setting the IP, we also noticed that the access door to the drive bays was a little flimsy and difficult to open via its magnetic-push latch.