Archive for the ‘Technology’ category

A look at my desk

September 28th, 2011

Whenever people visit my office or see my workspace, they are always amazed by the sheer number of screens.  The next question/statement is usually “what the heck do you need all those screens for”, or “you can’t look at more than one screen at a time”.

I’m not going to go into the awesomeness of multiple screens, but talk a little about how I have things setup.  To be honest, this is a reduction in screens for me, heres a pic from a previous office setup (theres actually another 3 screens on the left of me which you can’t see in that picture).

Anyway, the current setup, starting from the far left.

This is an XP machine, which I use mainly for Forex trading.  Although I prefer to work on OSX, and I know I could run this as a virtual machine, its just not the same experience, regardless of what any “tech gurus” might say – simply, they are disagreeing with me, and by default, wrong.  Kidding of course :)

When I sit in in “trading mode” on this machine, MetaTrader takes up both screens.  When not actively trading, I leave woopra.com up and running.  For those of you that haven’t seen woopra; its a real time website visitor analytics tool.  It displays visitor info/metrics in real time, including where in the world they are – which it maps (being a little boy inside, I find this very cool!).  At the time I’m writing this post, I can see there are 8 visitors viewing the zovo.co website, and which countries they are in, queue some sort of cheesy world domination music here.

The last screen on the XP machine runs Bloomberg TV, which occasionally gets muted, if you’ve ever watched Bloomberg TV, you’ll know why!  Another excellent web app is used here, check out zattoo.com, which lets you watch live TV channels.  Unfortunately the BBC feeds have been pulled now, but Bloomberg TV is there (which save me getting a Freeview TV in here).

Coming round to my much loved Macbook, running an Apple LED display (mini DVI straight off the macbook), and a Samsung LED (BX2350), running on an ezCap USB to DVI adaptor.

I do most of my browsing, document editing, chatting, etc on here.  The macbook screen gets used mainly for instant messaging and viewing youtube/ted.com etc.  The Samsung LED (on the far right) has all of my social media feeds via, Twitter OSX app, and TweetDeck as well as NewsBar (lightweight, no nonsense RSS feed reader).

Tell me about your desk/workspace, and feel free to ask any questions.  Usually a mention to @hamlesh on twitter will get a quicker response.

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I’m now IPv6 ready, are you?

September 28th, 2011

Cloudflare.com recently celebrated its 1st birthday, and to mark the special occasion it enabled its free ipv6 gateway.

I have a number of my websites setup with @cloudflare, its free, and offers a lot of security and optimisation filtering.  Its dead easy to implement and theres very little maintenance to do.  I highly recommend you check them out.

You can read more about the free ipv6 gateway for cloudflare users in their blog post.  Theres a really nice infographic on their post :)

Anyway, I’m now IPv6 ready – why aren’t you?

A look at my server room (at home)

September 14th, 2011

Here’s a sneak peak at the server / comms room setup I have at home. It evolves over time with new servers being put in as part of my personal test lab, but every once in a while I shut everything down, pull everything out, including power/network cables and redeploy. An evolving server room will always get messy over time, this is inevitable.

Be warned, this might be very geeky/techy for some of you, but I find it cool, and wanted to document/talk about it :)

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Going from top down;

Tv.drobo

4 bay USB2 drobo unit, currently running 2x 2Tb and 2x 1Tb drives. It’s a first generation drobo, thus only supports USB2, and max 2Tb drives, hopefully drobo will release firmware to support larger drives in the future. Once 2Tb drives drop below the £50 mark per drive (inc vat and delivery), or when I run out of space, I’ll replace the 2x 1Tb drives. This unit holds all of my TV episodes and shows, hence it’s name.

Dell PowerConnect

24 port gigabit switch, not much more I can say, it’s managed and very good in a “non ISP” environment. Not sure if I’d use one in the data centre though, other than perhaps as a storage network switch (supports multiple bonded port groups, and jumbo frames, with a 10Gpbs backplane).

Ironhide

Netgear ReadyNAS, with 4x 250Gb drives, holds all of my music. The main reason I still use the ReadyNAS is that it has squeezebox server built in as part of it’s base operating system. I have two jogglers (little openpeak photo frame tablet things) around the house, running jolicloud, with squeezecentre on them. So this setup for music “just works”, which is all I care about; for music anyway, throughput isn’t critical. If I needed to I could bond the network interfaces, but there’s really no need for that!

Allspark

1Tb Lacie Etherdisk (4x 250Gb) running Debian, this spends most of it’s time powered down, I only fire it up when I need it. It’s on a separate storage VLAN, and I use it as an NFS based datastore when I need to move virtual machines between different vmware ESXi servers.

Bonecrusher

1Tb Lacie Etherdisk (4x 250Gb) running Debian. This runs hellanzb and hellavcr, which knows what TV shows I follow, and grabs them when they are available (in the formats I like, ie hidef). Not going to go into too much depth on how these are setup, google, or ask me on twitter (@hamlesh) and I’ll tell you :)

Soundwave

Dell Poweredge SC1425, my primary vmware ESXi server, running various things, perhaps I’ll do another post about the virtual machines at some point. There’s usually another SC1425 (ESXi) called Optimus underneath this server, but at the time this picture was taken Optimus is in the office.

Sideswipe

Dell Poweredge 1800, my primary storage control server, and the central point for media sharing across the network. It also has some internal storage, about 4Tb worth, used when I need to move large amounts of data around.

Apple Xserve RAID

Multiple arrays deployed on this, mirrored for documents storage, two large arrays for movie and software storage. The throughput of these units is really something else, I need to put up the disk bench stats at some point. Having 14 spindles and fibre channel access (4 Gbps) is really something else, but some could argue, it overkill for a home setup ;)

I would like to get a pic when the xserve is working really hard, as all the blue indicator lights on the front are really quite mesmerising :)

Cabling is currently relatively neat, I have serious OCD when it comes to cabling neatness, still need to velcro tie the cables :)

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The Xserve RAID is running fibre channel to the storage server (Sideswipe), which has bonded gigabit onto the network (bonded ports on the switch too obviously).

There are some other machines missing in these pics, all that are used for various virtualisation testing etc, but they are currently with clients doing proof on concept delivery, or being borrowed by friends.

Everything is running on an APC remote reboot unit, so I can power cycle anything remotely, or usually when I’m feeling too lazy to go downstairs. I’ll have to do another post on my power provision at some point too. Ive built a custom distribution unit which can be switched between the mains, or a little petrol generator thats sitting in the garden (just outside the comms room)… Yep I have power backup / generator capacity for all of this kit at home :D

In total I probably have around 24Tb of storage running in this setup, all of which is backed up on zovo, who provide unlimited storage online backup. With everything running, this setup uses just under 4 amps (thanks to power metering on the APC power bar).

Anyway, hope this has been informative, why not comment and tell me about your setup?

Clone VM under ESXi using SSH

March 30th, 2010

So, you’ve deployed VMware ESXi and successfully deployed your first VM.  Now you are looking for the “clone” function that used to feature in the VMware Server of old.  I have some bad news, they’ve taken it away from the free VSphere management application – its now a feature you have to pay for.

“Thats ok, i’ll just SSH in and cp the files like I used to using VMware Server 2″… well, bad news again, its not that simple anymore.  You have to do a little bit of hackery, simple hackery mind :)

First step is to enable SSH on ESXi.

  1. Go to the ESXi console and press Alt+F1 – you will get a blank screen
  2. Type: unsupported and press <enter> (you won’t see anything as you type, but “Password:” will pop up)
  3. Enter the root password, press <enter>
  4. At the prompt type “vi /etc/inetd.conf”
  5. Look for the line that starts with “#ssh” (you can search with pressing “/”, or just press down to scroll)
  6. Remove the “#” from infront of the ssh line entries (put the cursor on the # and press “x” to delete)
  7. Save “/etc/inetd.conf” by typing “:wq!”
  8. Restart the management service “/sbin/services.sh restart”

Some people report that you have to manually kill and restart the “inetd” process using kill -HUP , but I didn’t need to do this.

You now have SSH access into the ESXi host.

Cloning a VM using SSH on ESXi

  1. SSH into the server (duh!)
  2. Locate the VM datastore (for me this was /vmfs/volumes/datastore1/)
  3. Make a directory for your new virtual machine
  4. Clone using “vmkfstools -i” (eg: vmkfstools -i /vmfs/volumes/datastore1/SOURCE/source.vmdk /vmfs/volumes/datastore1/TARGET/TARGET.vmdk)
  5. Cloning process runs (time to complete depends on size of SOURCE)
  6. In VSphere create a new custom VM as you would normally, and at the disk stage, select “use an existing disk” and browse to the TARGET vm that you’ve just cloned

Simples!

Oh, obviously the clone process won’t run if the SOURCE vm is powered on and running, you have to fully power it down.

As always, comments and feedback much appreciated – oh and talk to me on twitter :)

What does five nines uptime really mean?

April 6th, 2009

In the world of “online” and hosting, theres a lot kicked around about uptime, SLA, and “the nines”, and no, I’m not talking about a set of characters from a J R Tolkien saga, I’m talking 99.99% uptime, nines.

Having built hosting infrastructures for smes and bluechips alike, running Berkeley IT, and a number of “online related” or more to the point “infrastructure related” companies/projects, this is something I am constantly at a loss trying to educate others on. Thanks to the media (as usual, misinformation and the general media, who would have thought!), Jo Public tends to think that his 99.9% SLA uptime guaranteed by his US based reseller shared hosting provider is where its at.

“My online plate shop is critical to my business, it will never go down with XYZ company, they offer 99.9% SLA”… this is the type of drivle that Mr Jo Public can be overheard spouting, and at which point I tend to want to walk over and bash him over the head with a large banana, repeatedly, preferably one that has been dipped in liquid nitrogen.

Lets clear up a few things.

  1. Nothing can truly be 100% uptime guaranteed, as something can always go wrong
  2. A 100% uptime guarantee will cater for “force majoures” though, so dinosaurs coming back to live and rampaging through the datacenter, thats excluded from your guarantee
  3. 99.999% uptime is achievable, and usual involves multi level redundancy, including physical datacenter diversity – ie: your plate shop being mirrored in a different physical datacenter
  4. Usually you would need multi level redundancy for this, all the way up the chain, power, network, distribution, data, component – not something thats cheap to deliver – although for infrastructure people it is easy ;)
  5. 99.9% uptime SLA is usually what most providers would look to offer as standard
  6. EXPECT TO PAY A PREMIUM FOR 99.999% - if you aren’t paying a premium, and your hoster claims the nines, then its about as likely to be “five nines” as I am to suddenly wake up and find that I have the powers of spider man
  7. the SLA will usually outline your reimbursement if there is unscheduled downtime, if it doesn’t, move your business elsewhere, as the SLA and uptime claims just aren’t worth anything
  8. that word in point 7 is important, “unscheduled“, most, if not all providers will exclude “scheduled maintenance” from their uptime guarantee, make sure that your SLA outlines how much notice will be given before this work, and how long work can realistically last for

Now to quantify a few things;

  • 99.999% uptime SLA quantifies to 0.4 minutes of down time a month or 5 minutes of downtime per year
  • 99.99% uptime, 4 minutes per month, 52 minutes per year
  • 99.9% uptime, 43 minutes per month, 8 hours and 46 minutes per year
  • anything less, theres no point

Pingdom have actually put a really nice little PDF guide together for this, check it out.