Category Archives: Hardware

Dell Latitude Numbering- 2017 Edition

Ever wondered what those four-digit model numbers used on Dell Latitude devices (for example “Latitude 7275”) mean? This helpful guide should answer your questions.

Dell Latitude Laptop

First Digit

This shows the range the device belongs to. 3 is used the entry level “Essential” models, 5 on the mid range “Mainstream”, and 7 the high end “Premium” devices. Also referred to as the 3000, 5000, and 7000 series.

Second Digit

The second number indicates the screen size. A 2 means the screen is roughly 12” diagonal, 3 means 13”, 4 means 14” and so on. For example the Latitude 7280 has a 12.5” inch screen

Third Digit

The third digit indicates the generation. At time of writing (Jan 2017) we’re currently seeing the tail of the generation 7 models (primarily based on the Intel Skylake chipsets), and the start of the generation 8 (primarily “Kaby Lake” but some Skylake devices will be available for Windows 7 compatibility)being released. Models are roughly equivalent between generations- for example the 7270 is superseded by the 7280 both are premium laptops with roughly 12 inch screens.

Fourth Digit

The final digit currently denotes the type of device. A 0 indicates a traditional laptop, a 5 indicates a device with a detachable keyboard (the style of the Microsoft Surface Pro)- for example the Latitude 7275, and a 9 indicates the new convertible, fold-back, device (similar in style to the Lenovo Yoga devices).

ESXi UNMAP not working on Replicated EqualLogic Volume


  • The VMware vSphere ESXi UNMAP command doesn’t release space on some or all volumes on a Dell EqualLogic SAN array running v8 firmware (may apply to other versions too). Using the following command in an SSH session to a 6.0u2 host (again, will apply to other versions):
    esxcli storage vmfs unmap –l MYVOLUMENAME
  • The volumes are VMFS5 (and always have been- they haven’t been upgraded from VMFS3).
  • Replication is enabled for the volumes that won’t rethin.



UNMAP doesn’t work on the EqualLogic when Replication is enabled. It doesn’t return an error to the SSH session, and the temporary rethinning file is still created, but the disk is not thinned.


Disable replication on the volume, re-thin the volume using the UNMAP command, then re-configure replication. Unfortunately this means the entire volume must be re-copied to the replication partner and this may impact bandwidth usage and replication schedules on larger volumes.


Backup Clock

In a tangent from my regular IT activities, I’ve made a clock for the IT office using an old tape reel, a floppy disk, and an analogue clock kit from Amazon. It’s turned out quite well and looks like this. Here’s a (very) quick guide on how to make one of your own.

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The Home Lab

New NUC Based Home Lab

Inspired by the folks at the London VMUG, I finally got round to starting on a proper home-lab for the bits of hands-on IT learning that I can’t do with a Virtual Machine on my laptop, VMware Hands on Labs and the like. I’ve based this around the 6th Generation Intel NUC (“Next Unit of Computing”) platform. Hopefully this balances my requirements of budget, computing power, electric usage, and noise output (this is a HOME lab after all). I want the platform to be flexible, being able to run different hypervisors, operating systems, and applications depending on what I want to experiment with at the time.


  • Intel 6th Generation NUC NUC6i5SYH barebones system
  • Samsung 250GB 850 EVO M.2 SSD
  • 60GB 2.5in SSD (Recycled from an old laptop)


The Components of the Server

The NUC is a small but very solidly built piece of kit. The lid pops off by undoing four captive screws in the feet (awesome idea this- you’re not going to lose the screws if they stay attached!) revealing the insides.
NUC Insides

Inside the 6th Generation NUC

All the necessary slots are easily accessible so it was straightforward to fit the SSDs and memory- the only additional tool required was a smaller screwdriver to work the M.2 retaining screw. With the parts fitted the case slotted neatly back together and the four screws in the feet were tightened, the task took only a couple of minutes to complete.
The M.2 retaining screw

The M.2 retaining screw

Next Up: Installing the ESXi Hypervisor on a 6th Generation Intel NUC

Microsoft Wireless Display Adapter


Display Screen With Wireless Display Adapter Connected

Last week a Microsoft Wireless Display Adapter turned up in the post. I’ve tried some wireless PC display connectors before, and the general rule seemed to be they were clunky, unreliable, and not that user friendly. This however, changes that. This is WiDi/ Miracast as it should be; easy to set up and simple to use.
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