|At a Glance|
|Product||Sans Digital MobileNAS Linux NAS + iSCSI 4 Bay Network Storage Server Tower (MN4L+B)|
|Summary||High-performance four drive RAID 5, 6, 10 NAS with root access and console connections.|
|Pros||• High Performance
• Extensive protocol support
• Multiple RAID volumes
• VGA root level console support
|Cons||• Poor documentation
You have many choices when choosing a Network Attached Storage (NAS) device for your home or small-office these days. Choices range from a simple, small-single disk unit all the way up to a multi-disk RAID product loaded with features. And when high-performance is a concern, it's increasingly common to find gigabit Ethernet as part of the package.
But even though it's available, I've found that most desktop NASes really lack the horsepower to take advantage of their gigabit capabilities. Generally, these devices have a relatively slow CPU with little RAM available for caching.
But in this review, I'm going to check out a NAS that breaks that mold. The Sans Digital MobileNAS MN4L+B is a four-disk , RAID NAS that packs a real punch. Along with its gigabit Ethernet (with jumbo frame support), the MN4L+ comes with a 1.2 GHz Intel Pentium M and can be ordered with up to 2 GB of DDR2 RAM to maximize cache.
The MN4L+B can be purchased with or without drives, but the unit supplied for review came with four Seagate ST3100340AS Barracuda 7200.11 1TB SATA drives installed. The operating system is installed on a 1GB SSD drive so you can boot up with no other drives installed.
I should note that the Plus is actually available in five models in each of the two colors. The base model comes without drives and the 1T, 2T, 3T and 4T suffixes to the base model numbers indicate four 250 GB, 500 GB, 750 GB or 1 TB installed drives, respectively. (Sans Digital says that it uses Seagate 7200.11 drives and sometimes Hitachi T7K250 for 250 GB.)
There are also "2G" versions (MN4L+B2G and MN4L+2G) available that bump the 512 MB of memory to 2 GB. If you want to upgrade RAM yourself, you can install your own DIMM without voiding your warranty, although it's a bit difficult to get into the box. Figure 1 shows the back panel of the unit.
Figure 1: Back Panel
The case itself is heavy metal and feels fairly sturdy. You'll notice that along with the standard power and USB ports you normally have on these units, there's also an external SATA (eSATA) port and two ports you don't often see: Firewire 400, and VGA. I've never previously seen Firewire on any of the NASes that I have tested, and VGA support is also quite rare.
Having VGA support means that if you really get in a jam with the box and can't contact it on the network, you can hook up a USB keyboard and mouse, plug in a monitor and log in locally to diagnose the issue. It's a nice feature, if you know your way around a Linux command-line , since that's what the Plus is running (more details later).
You'll also note that the fan vent is on the large side, which usually indicates lower fan noise. Unfortunately, the Plus' fan is loud while running. When the box is booted with the four drives in use, it draws around 60 Watts, so compared to other NASes I've worked with, the greenness rating of this box would make Al Gore cry, particularly because it lacks idle drive spindown and programmable shutdown / startup features.
I'll note at this point that I had some issues with the power connector seen just above the Firewire port. The connector seemed to be quite touchy so you'll need to be careful with it. A number of times when I was fiddling around with cables or adjusting the position of the Plus, I lost power. The back panel could definitely use a cable tie-down, like I've seen on other products.
One thing that doesn't show up in the picture is second hidden eSATA port underneath the first. Sans Digital says that this port is not exposed because the license of the internal OS supports the use of only a single eSATA port. But the port would be fully functional under a different OS.