Review: Western Digital WD Sentinel DX4000 Storage Server

You’ll have heard of Western Digital, of course. The company has been selling all manner of storage equipment for many years, from internal hard drives through to external hard drives and more recently, at the top of the tree, the Sentinel DX4000 Storage Server.

The Sentinel DX is a “serious” storage server for small and medium businesses – forget backing up your files to a direct attached USB drive, what you need to support your business – according to WD – is a server. Packing Microsoft’s Windows Storage Server 2008 R2 Essentials (from the team that brought you Windows Home Server), the Sentinel DX4000 is a four bay device which allows you to store, share and protect your business critical data across PCs and Macs in your small or home office.

It’s up against some tough competition out there – we’ll put the Cloud aside for now, although that’s an increasingly viable option for businesses wishing to protect and provide easy remote access to non-sensitive data. Otherwise, at the bottom end of the market, HP has been shifting a lot of their aggressively priced ProLiant Microservers to homes and small businesses around the world. NAS vendors such as Synology, QNAP and ASUSTOR have been packing their devices with higher quality operating systems as well as a swathe of consumer and business oriented apps.

On the Windows OS side, Microsoft has continued to offer Windows-based server options for small business – the release of Windows Server 2012 Essentials last year confirmed that this was a market that the company has at least some interest in, although pre-packaged options from OEMs have been thin on the ground. Western Digital have yet to offer a server with Microsoft’s Server 2012 Essentials, opting instead for Redmond’s earlier Storage Server line on the Sentinel – with a plethora of options on the market for small business owners, they’ll be hoping a combination of brand strength and Enterprise grade hardware persuades you to direct your spending their way.

That business grade positioning is most obvious in the company’s choice of storage hardware – our 16TB review unit shipped with four Hitachi Deskstar 4TB hard drives – optimised for speed and reliability, according to the marketing blurb, but alongside the cost of the Windows OS, most definitely contributing to a high price point. You can expect to pay up to £1549/$1809 for the fully-loaded Sentinel – a worthwhile investment? Let’s take a look.

Whilst WD have previously focused their storage devices at the consumer, the Sentinel arrives in “business formal” brown cardboard packaging – signalling clearly that the Sentinel is positioned for small business. In that sturdy carton you’ll find all you need to get the DX4000 up and running, including the Storage Server itself, twin power adaptors (an optional extra, allowing the server to continue working in case one PSU fails), an Ethernet cable and a quick install guide.


Whilst the outer box is large, it belies the small footprint of the device itself which is very compact for a server at 22.3 x 16 x 20.8 cm (6.3 x 8.8 x 8.1 inches). With professional positioning, you’d expect the DX4000 to look the business and WD have done a good job with the Sentinel’s industrial design – although the black plastic front panel and side opening storage door takes the edge off an otherwise premium feel. Open up the door, however, and the four drive bays are robustly built – hinged from the base, each bay opens downwards and allows your drives to slip in easily.

As mentioned, our top-of-the-range review model shipped with Hitachi GST Deskstar 5K4000 4TB hard drives (Hitachi GST is now a fully owned subsidiary of Western Digital, in case you were wondering where the WD-branded drives were at). This is a high-capacity, low-power version of the desktop drive which is optimised for quieter operation and  power consumption. As you’ll see below, alongside the massive volume of storage these drives provide (16TB gives you around 11.5TB of usable storage in a RAID5 array) they’re pretty nippy too – these aren’t your bargain basement drives, but they’re not your average drives either.




The front of the server includes an LCD display panel, offering status information and alerts as well as a physical power button and LED indicators for power and storage status. A scroll button to the right allows you to leaf through the information provided in the LCD panel, but unlike some of the Sentinel’s NAS competitors, you can’t really control the device from the front panel. Around the back, there are the aforementioned twin power ports – not unique in storage servers, but reasonably rare in devices positioned for small business and a welcome addition for those needing robust performance and access to their critical data. Twin Gigabit Ethernet ports are also provided, allowing the device to switch to a second network connection should the first fail. WD state network read speeds of 85 MB/s via a wired connection – not the fastest on the market today by any shout, but certainly good enough for most small business use.

If the onboard 16 Terabytes of storage aren’t sufficient for you (cheaper models with smaller drives are also available) then storage expansion is supported with two USB 3.0 ports fitted – they’ll deliver up to 5 Gb/second storage rates.

The Sentinel is powered by Intel’s trusty Atom D525 processor – a 1.8GHz dual-core processor that may be getting a little long in the tooth in processor terms, but is a popular choice for SMB and home server manufacturers. WD have paired the Atom with 2GB RAM which provides plenty of oomph for the server storage role fulfilled by the DX4000. Look around and you’ll find storage devices with faster processors (Intel Core i3s are emerging at the top end of consumer NAS) and slower ARM-based chips, but the Atom remains a decent choice for SMB use.



  1. The DX4000 has been for me a huge disappointment. The NAS is compatible only with Western Digital Enterprise class hard disks, but among them you should order a specific (and very expansive) model compatible with DX4000 (difference being only the 17th code in the p/n with respect to the same HD which can be used elsewhere). There is no possibility to control the RAID system: RAID 1 or 5 is controlled by the NAS, downgrade or control is just not possible. In case of failure RAID rebuilding (which you cannot control, it is fully automatic) might take days. Once the NAS is configured there is no way for instance to change the server name, only possibility is to reinstall and reconfigure completely the NAS. With regard to noise this is for sure not the NAS to be kept in a small room. Last but not least all the operating system is on the server HD and not on a dedicated internal hard disk. In case you need a reinstall the process is cumbersome, you need to boot from a USB stick created ad hoc and the whole process, which requires some hours, needs also control by a dedicated software to be installed on a virtual DVD on your workstation! I hope WD made improvements with the newer units because the DX4000 has to many CONs with respect to very few PROs

    1. I concur. These things are junk. I have had nothing but problems with the WD-Sentinel we deployed. It’s main hard drive failed and took over 3 months to get it resolved with WD Support. Now it has an error that the BIOS is degraded. Every time I restart it through Windows, it never comes back up and I have to manually power down the server and restart it. Garbage, Garbage, Garbage.

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