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Further to I have now received my new hardware and had time to think and experiment.

My first experiment was iSCSI vs NFS. I created 2x 2-disk RAID0 Volumes on the Synology DS 1813+ (using the 4x Samsung EVO 840 SSD) and attached them to my new ESXi host. I then installed a clean Windows 7 VM on each volume. After installing windows I did some file copies and made a few notes.


The graph above (along with the figures in the table) do a great job of showing the results. NFS cam out over 20% faster. You can see the max read speed recorded as 93 MB/s (only 71 MB/s for iSCSI) and write rate recorded as 77 MB/s (only 62 MB/s for iSCSI).

I then ran Crystal Disk Mark on the iSCSI VM:


And the NFS VM:


Here some of the results are less of an improvements, but others are more than doubled. All of the above ruled iSCSI out for me.

But I then got thinking about local storage. I only run one ESXi host these days (I have a spare host ready to swap out if I need to, but to save electricity I only run one at a time), so the benefit of networked/shared storage is almost non-existent (I will be backing up snapshots to the NAS).

I couldn’t initially create a 2 disk RAID0 array because ESXi doesn’t support my motherboard’s onboard raid, so I stuck with a single local disk (the Samsung EVO 840 SSD again); Installed Windows 7 and ran the Crystal Disk Mark benchmark:


I then found an old PCIe SSD (OCZ Revodrive x3) and thought i’d give that a try more out of interest:


Nice! Unfortunately the PCIe SSD isn’t directly supported in ESXi so I had to create a normal VM and connect the SSD using passthrough. This would essentially mean it could only be connected to one VM (which wouldn’t be a huge problem as I’d want to connect it to my SQL VM) but the stability isn’t great either.

I picked up a cheap LSI SAS3041E raid card from eBay and went about setting up the local 2 disk RAID0 array. The results were very surprising:


These are all below the speeds seen using a single SSD. See the below table to easily compare:

I’m not sure whether this is because the raid card, or the lack of TRIM support or some other obscure reason. I decided i’m happier running 2 separate SSDs anyway (I can split SQL db & logs between the two discs to see a performance boost) and if something goes wrong I will only have to restore half my VMs from nightly backup.

iSCSI NFS Local Single SSD Passthrough PCIe SSD Local RAID0 2x SSD
Seq Read 96.74 101.4 238.7 1371 233.4
Seq Write 30.61 72.91 229.1 1089 219.9
512K Read 74.77 74.48 228.3 1051 210.1
512K Write 45.46 66.23 223.8 1010 208.2
4K Read 4.138 5.213 22.92 30.36 18.31
4K Write 4.337 4.781 52.73 68.65 23.59
4K QD32 Read 6.575 8.661 212.8 281.1 62.26
4K QE32 Write 5.582 8.791 199.7 240.9 92.81

Screen Shot 2014-04-25 at 16.20.55



And another without the PCIe SSD to make it a little easier to compare:

Screen Shot 2014-04-25 at 16.26.58

So, in conclusion- I will be running 2 of the 250GB Samsung EVO 840 SSDs locally in the ESXi host. This will provide optimal performance and hugely reduce my dependance on the network and NAS (currently the VMs live on the NAS and I can’t take it or the network down without powering everything down first; my pfSense software router resides in a VM too, so I lose internet connectivity!). I will continue to use Veem to take nightly backups should anything go wrong with the ESXi host.

I hope to migrate everything over the weekend- fingers crossed.

Solar Update

I posted some details back in October when I had my solar panels installed

I thought i’d provide a little update to show how much i’m getting out of them;



This shows my best day so far.


This shows a daily summary for the last 40 days.


And for the last 12 weeks.

To give you an idea, i’m on a feed-in-tariff paying roughly 17.5p/kWh so on my best day 23kWh earnt me £4. Not to mention that based on the estimation that i’m consuming 50% @ 13.5p that’s another £1.50.


And one last screen showing average daily generation through the winter months. Making a mere 50p/day :)

New Lab / NAS

Far too long since the last post. Let’s hope this will be the start of them picking back up again!

I have been experiencing some performance issues and need to have a bit of a re-shuffle of the servers/network (my vCenter appliance has stopped working, SQL is being slow etc). I have some production stuff running and don’t want to take everything offline for long so decided to build a new environment then migrate stuff.

I wont be changing much; 

Old NAS; Synology DiskStation 1812+ w/
-4x 3TB WD Green in Synology Hybrid Raid (SHR) : Main data store for Movies, PVR Recordings, ISOs, Photos etc (CIFS & NFS)
-2x 256GB OCZ Vertex4 SSD in RAID0 : Virtual machine storage (NFS)
-2x1gbit LACP to switch
Old ESXi Host; SuperMicro X8SIL-F w/ Xeon X3470 & 16GB RAM running VMWare ESXi v5.1
Old switch; Linksys SRW2024W

New NAS; Snology DiskStation 1813+ w/
-3x 4TB WD Red in Synology Hybrid Raid (SHR) : Main data store for Movies, PVR Recordings, ISOs, Photos etc (CIFS & NFS)
-3/4?x 250GB Samsung EVO 840 SSD in RAID0? : Virtual machine storage (NFS/iSCSI?)
-3x1gbit LACP to switch dedicated to main data store
-1gbit to switch dedicated to VM storage
New ESXi Host; SuperMicro X8SIL-F w/ Xeon X3470 & 32GB RAM running VMWare ESXi v5.5
New switch; Cisco SG200-26 (separate vm storage traffic on it’s own VLAN/subnet)

You’ll notice a bunch of questions marks around the new Virtual machine storage volume. I’m currently debating which disk configuration to use and which storage protocol. I’ve always used NFS as it seems much simpler but understood iSCSI to be the better option (especially with the Synology supporting VAAI hardware acceleration). But despite this, i’ve been reading that NFS seems to outperform iSCSI.

Additionally, if I go iSCSI I will try using 2x1gbit ports and enabling multipathing / round-robin. If I go down the NFS route I don’t think LACP will provide any benefit as the IP hash from a single ESXi host to the single DiskStation will always use the same link?

I have 4 of the EVO SSD so am initially creating a 2 disk RAID0 volume using NFS and an identical volume using iSCSI. I can then try running some like for like comparisons/benchmarks to determine which configuration to use going forward.

I will provide an update shortly.

Further 433Mhz RF Hacking

Further to

I noticed some referral traffic coming from Erlands blog:

He used on his arduino to receive/interpret the 433Mhz traffic and it works a treat for the cheapo PIR, door/window sensors, smoke alarms etc

4f77d093 1440 4530 b3c1 283ec01a57f9

Here is a sample output from one of the door sensors. It quite rightly identifies the state 0/1/F of each jumper:

Decimal: 1398131 (24Bit) Binary: 000101010101010101110011 Tri-State: 0FFFFFFFF101 PulseLength: 525 microseconds Protocol: 1
Raw data: 16344,540,1560,544,1564,544,1560,1588,508,540,1568,1584,516,540,1564,1588,512,528,1576,1580,524,536,1576,1576,524,528,1584,1580,524,528,1584,1576,528,524,1588,1576,540,1572,544,1572,544,520,1604,520,1604,1572,544,1568,552,

I'm in the process of firing up a new Raspberry Pi DomitiGa server. I will use a JeeNode connected via USB Serial to receive 433Mhz traffic alongside 868Mhz JeeNode traffic. I guess I can probably get rid of my RFXCom 433Mhz transceiver now?

I’ve booked a holiday to Thailand over Christmas and decided to buy a quadcopter so I could get some different photos & videos while i’m away. It’s great fun!

Here’s an aerial shot from a local park:


And a video of the first flight with the Zenmuse Gimbal installed:

And a few shots of the local tennis club:



And video:

Still working on getting a decent FPV setup and learning to be gentler with the controls (I may end up adjusting in software to make them less sensitive).

Despite still having a handful of unfinished projects I decided to take the plunge and have some solar panels installed. I found a local MCS accredited installer MAH Solar Solutions and in no time had the kit up and running. My house faces east/west so I have 8 panels on each side.


The panels are Canadian Solar 250W, total 16 to form a 4KW system fed into a Aurora ONE/PVI 3.6 inverter in the loft.


The solar install was the perfect opportunity to finally replace my ancient fusewire consumer unit. Which got me to thinking of ways I may be able to better monitor my energy consumption. I hoped to find “a magical fuse box” but hours, days, weeks of research and the best solution I could come up with were DIN rail mount KWH meters.

Unfortunately no amount of searching could find a single image of the KWH meters in use or a diagram of how to wire them in a consumer unit. Instinct told me to have each meter mounted alongside each breaker, but this would prevent me from using the busbar. Then I thought about mounting them upside down, but this would cause similar issues and mean running the neutral far too close to the busbar! The next idea was to either mount 2 consumer units side by side, having the breakers in one and the meters in the other… Then I found some information about twin/dual rail consumer units which seemed like a winning idea.

MAH Solar Solutions were to be installing the new consumer unit and despite having never seen or used the KWH meters before they were more than happy to install them. They came up with the idea of mounting the meters at the end of each block of breakers. With a big enough consumer unit this meant the busbar could still be used. I will try and add some diagrams and more images at a later date.


I’m still working the best way to read so many pulse counters simultaneously and log/process the data. Currently looks like one of the most promising, but I will need to start from scratch with a way to count, store, transmit etc. So for the time being I decided on the fluksometer which can handle 4 pulse inputs- which will do for now: mains, solar, oven & gas meter.


The flukso service itself provides quite nice graphing- you can see here my mains consumption (blue), oven consumption (green), solar pv generation (red) and gas consumption (orange).


Which feeds nicely to


You can see the rj11 cable coming out of the gas meter (to the fluksometer). The purple cable runs from the RS485 port on the inverter in the loft. I am waiting on a USB to RS485 device so I can start pulling some detailed data using Aurora Monitor or similar.


I understand the fluksometer has an onboard RFM12B configured on the 868Mhz band to understand communication from jeelabs devices- which is ideal as I meter my water using jeenodes.


I just don’t know how to get them talking… yet!

Unfortunately a growing trend- this blog has been neglected (I will try and get back on top of things eventually!). But here’s the most recent reason why…

I am now the proud owner of a new photo blog

The site was previously run by two brothers Charlie and Tom. Each day bringing a new photo (for everyone) along with a description for those of us curious as to how the picture was captured.

The blog used WordPress, the same as this one, but unlike this one it is not hosted at which gives a much greater ability to customise. Fortunately my background made it quite simple to dive in and start making some of the changes I hoped would enhance the site:

Random Photos

  • Create a category called random (don’t attach any photos as they won’t be browsable)
  • Modify your theme’s archive.php

Add this above if (have_posts()):

$special_random = false;
if(is_category('random')) {
$special_random = true;
query_posts( array( 'posts_per_page' => 5, 'orderby' => 'rand' ) );

Then modify the next_posts_link code (clicking it on the random page would fail… you just need to refresh the page to see more random posts):

if(!$special_random) {
next_posts_link( __( '« Older Entries', 'andrea' ) ); 
  • Install and activate the plugin page links to
  • Create a page and select “page links to” at the bottom and point to your category page (something like http://yourblogurl/random)- this will add the random photos link to your navigation menu

Thumbnails on Search / Category / Tag pages

  • Modify your theme’s search.php
<div id="post-<?php the_ID(); ?>" <?php post_class( 'entry-content' ); ?>>
<a href="<?php the_permalink(); ?>" rel="bookmark">
if ( has_post_thumbnail() ) {
the_post_thumbnail( 'photo_thumbnail', 'class=photo_thumb' );
} else {
// the current post lacks a thumbnail
<?php the_excerpt( __( 'Read the rest of this entry &raquo;', 'andrea' ) ); ?>

Here’s a few of the latest images:

Church of the Good Shepard

The Walkers

I suggest you check it out :)


Canvas Order

Finally found the time to sift through my photos and send a bunch to be printed on canvas to fill my rather bare walls:

A really old shot of Brighton seafront from the pier.

A recent shot from St Louis, MO.

One of the first photos I ever took looking across from the north side of the Thames in London.

A recent photo from Miami, FL.

Another old shot taken at Tropical Wings in South Woodham Ferrers.

A recent shot from Koh Phangan.

A recent shot from Koh Tao.

A recent shot from Koh Nang Yuan.

A recent shot from the Grand Canyon, NV.

And one last shot from Vegas, NV.

I think I got a pretty good deal- from all 2:1 at 40" x 20" @ £33.95 but with the current 20% discount code UKSPRING20 came in at £27.16 each. Let me know if you know anywhere cheaper!

I’ve not been following it this year (due to the schedule change), so I’m playing catch up! Here they are for anyone that missed it:

You can find season 1 here:

Thanks Chris, keep up the good work!

I’ve still yet to pick a few favourites from Thailand, so until then, here’s a few from recent nights out/at work:

Wax @ the Sunrooms

W0rks @ Mansion

After Office Hours (AOH)

Kool Kids Klub @ the Sunrooms


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