A late entrant in the crowded Network Attached Storage (NAS) market, the Sentinel DX4000 certainly stands out from the competition and for a number of reasons. To begin with, it’s from disk manufacturer Western Digital and, unlike a lot of others, comes pre-configured with disks inside ready to start working. It also differs in that, instead of a variant of Linux, it runs Windows Storage Server 2008 R2 although that, as it turns out, could be something of an Achilles’ heel as far as the average small business is concerned.

What’s in the box?


Hardware wise the Sentinel DX4000 is well up with its rivals and looks the part. What you get is smart black cube, clearly designed for desktop deployment, built around a robust, mainly metal chassis with a front door giving access to the drive bays. There are four of these in total, to take 3.5-inch disks with a neat tray-free design whereby disks just slide into place. Unfortunately it’s not possible to lock the disk in position or lock the outer door itself, which could be an issue with some buyers.

A small LCD status panel is located at the front, while power is provided by a large external AC adapter with two power sockets at the back for redundancy?unusual on a storage appliance in this price bracket. However, you do have to buy another supply to take advantage of this option.

Power management options are limited and for some reason. The noisy fan continues to run when the power is switched off unless you completely isolate the Sentinel DX4000 from the mains supply. Also at the back are two USB 3.0 ports which can be used to attach external storage. The network interfaces are, likewise, located at the rear with two available, again, for redundancy. In theory the Gigabit ports could also be combined to boost bandwidth but this isn’t a pre-configured option.

Storage options


Two models of the Sentinel DX4000 are available fitted with either two or four 2TB SATA drives, also from Western Digital, of course. With two disks installed the price asked is £599 (ex. VAT), while the fully equipped version will set you back £899 (ex. VAT). Opt for the two-drive model and the disks will be delivered as a RAID 1 mirrored pair for the ultimate in redundancy, albeit at the cost of halving the effective capacity.

The 4-drive appliance is better off in this respect in that you get a RAID 5 array, but either way the RAID protection is provided in software and re-building an array should problems occur can be a very lengthy process. On the plus side additional disks can be easily added to the two disk model and, although not advised, you don’t have to stick with Western Digital drives. Moreover, when a third disk is added the array is automatically upgraded to RAID 5 without the need for user intervention.

Power behind the throne


The processor inside the Sentinel DX4000 is a 1.8GHz dual-core Intel D525 Atom, accompanied by 2GB of memory. Running the Essentials edition of Windows Storage Server 2008 R2, this enable the Western Digital unit to service the file sharing needs of up to 25 clients. As such it is very much a small-business solution, albeit one based on the tried and tested Windows Server platform and able to support not just Windows but Apple Mac and Linux/UNIX clients as well. Another advantage of running Windows rather than Linux is the ability to use Remote Desktop to connect to the Western Digital server and manage it directly.

However, one of the big issues with Windows Server as far as the SMB is concerned is the level of technical expertise needed, so there’s a much simpler Dashboard tool which can either be run on the server or a remote Windows PC to take care of common management tasks. Using this tool we were quickly able to configure server options such as remote Web access and set up users accounts as well as create new file shares in addition to those already provided.

Performance was reasonable given the specification, and on a par with Linux-based products in the same bracket. However, you are limited to using the Sentinel DX4000 as a NAS server with no easy way of configuring the iSCSI support which (in theory) is there in the Windows software. Which is a shame, especially given that most other small business storage appliances now provide iSCSI support straight out of the box.

Client issues


Little has to be done to get the Sentinel DX4000 up and working, and once the initial steps are completed it appears on the network like any other Windows server. However, for maximum benefit users need to point a browser at the Western Digital server to download and install a custom client connector. This enables backups to be taken of client PCs and for the management dashboard to be run remotely.

Unfortunately installation is a fairly lengthy process, requiring the latest .Net framework to be installed and, in our tests, the connector failed to install properly, if at all, on quite a lot of PCs? including those running Windows 7. We were also disappointed by the lack of options when taking client backups and the absence of tools to backup the server itself, although an online backup capability is promised.