Tag Archive for SQL

Amazon AWS Tips and Gotchas – Part 2 – AWS EBS & RDS MS SQL

Continuing in this series of blog posts taking a bit of a “warts and all” view of a few Amazon AWS features, below are a handful more tips and gotchas when designing and implementing solutions on Amazon AWS, including EBS and MS SQL on RDS.

For the first post in this series with a bit of background on where it all originated from, see here:

For more posts in this series, see here:
Index of AWS Tips and Gotchas

AWS Tips and Gotchas – Part 2 – EBS & RDS
  1. You cannot increase the size of EBS volumes without stopping the instance. If you are designing scale-out / high availability solution then this is not a big issue as you should be able to take some downtime on any individual node, but that downtime is going to be fairly significant, and the larger the volume, the more downtime you will incur. The actual process looks like this (summary below):
    • Stop the instance
    • Snapshot the volume
    • Create a new volume from the snapshot, with your new larger size
    • Detach the old volume
    • Attach the new volume and start the instance back up

    This is one of those features which is bread and butter for a vSphere or Hyper-V admin, and could be done online in seconds with the vast majority of guest operating systems.

    I think it really highlights the key difference between designing for AWS Cloud, and a traditional enterprise virtual infrastructure. In a solution where most of your hosts are ephemeral, this should not be a big issue. If you try to take a traditional enterprise approach, you may find yourself in hot water, having to take service downtime to make simple changes.

    I suggest where possible / appropriate, avoid using EBS and use alternative options such as S3 which can scale on demand.

    UPDATE 13th Feb 2017: Amazon have just released Elastic Volumes, which allow you to scale up EBS volumes on demand! Yay! More info here:
    Amazon EBS Update – New Elastic Volumes Change Everything

  2. Similar to resizing EBS volumes, you cannot hot-resize an instance, or indeed resize them / change their type in place. In order to change instance type you need to detach any EBS volumes (including root volumes if you wish to maintain them too), terminate the instance, create a new one and re-attach your volumes.
    Obviously you cannot re-attach a root volume if you are using instance storage (ephemeral) for this, so make sure you use EBS backed volumes if you want to maintain your root volumes for any scale-up elements of your solutions which cannot simply be re-created from a bootstrap script.
  3. If your application depends on Microsoft SQL, you are going to be in for a fairly unpleasant surprise! It is not currently possible to resize MS SQL volumes on Amazon RDS once they have been deployed! At all. Full stop. Nada.AWS MS SQL - say what nowThe recommendation from AWS is to deploy your estimated future capacity requirement from day one! Not very cloudy at all…Your only growth option when you hit your initial capacity limit is to migrate all the data to a new RDS instance and take some application downtime to fail over.This can be minimised by using things like log shipping from the source instance to get the target as close to up-to-date as possible, but you will still need to shut down and swing your applications, and frankly it’s a risky headache which would be better avoided if possible, and certainly not something you want to be doing on a regular basis.Probably best to design for your estimated growth, and add a percentage on top.

Find more posts in this series here:
Index of AWS Tips and Gotchas

Amazon AWS Tips and Gotchas – Part 3 – S3, Tags and ASG

VMworld Europe 2015 Day Two Roundup

Doesn’t time fly by fast when you’re having fun?! Day two was frankly a full-on brain cram fest for me…

The morning started off with the keynotes, which (if I’m honest much like the US announcements) were interesting but not earth shattering for me.

It was nice to see Claranet featured for the second year running in the keynote speech though!

I will leave it to others this year to summarise the announcements, but the coolest new product which peaked my interest was vSphere Integrated Containers.

VIC is more than simply the ability to see containers running inside of a VM. In actual fact it allows you spin up containers within forked VM clones on a one to one basis, where the additional RAM and storage are copy-on-write. All this in about the same time it would normally take you to launch a standard container natively. As the VM is then subject to the usual features and benefits of a standard VM, you have the ability to control it’s access, security and performance at a very granular level.

To the developer this still uses the standard docker interface, but the infrastructure admin can manage things through vCenter as they always have done. Of course this means you are also subject to the usual limits on vSphere (for example up to 10k objects per vCenter), so this is not hyper scale, but lets be honest, how many of us are actually doing that? VMware also have a solution for this scale, Photon platform, but I’ll save that for another day.

I had a quick trip to the VMware Video Game Container System later in the day where I had the opportunity to spend 20 minutes chatting with one of the VMware CNA Product Managers about some of their roadmap developments, and suffice to say the future looks very impressive! They also demo’d the ability to containerise virtually any operating system; they were actually running MS-DOS containers and Prince of Persia inside of them! If you want to learn a bit more about CNA, check out the intro blog on the VMware website:


Later in the morning, I was kindly invited to a vExpert vRA.next Workshop in the HoL where we were lead through the latest features and improvements in vRealize Automation. There certainly seemed to be something for everyone, significant improvements in the speed and method to deploy which made a lot of people very happy, as well as a rationalisation of the server roles. The only thing which was a slight downer for me was the fact that true multi tenancy is not quite there yet in the product.

After a quick bite to eat, including some English Bread Triangles, I managed to get a bit of time wandering round the fringes of the Solution Exchange. Hiding at the back of the hall I came across a really interesting new security startup who only recently came out of stealth and went GA just this week, called GuardiCore. Amongst many other nifty features, their software can monitor for any blocked / dropped packets from potential attackers, and immediately redirect the potentially malicious session to a honey pot machine, logging all further communications with and actions of the attacker.

GuardiCore leverage NSX in a big way, avoiding the need for agents within the guest OS, but can also work with vanilla vSphere if that’s your (more likely just now) platform. Their demo was excellent and I will definitely be keeping an eye on them in future. If you happen to be passing booth E149 I recommend you stop by for a chat, it will definitely be a good use of your time!

The afternoon was spent mostly in sessions, including the highly popular VAPP5129 – Database Virtualization: Doing IT Right with vSphere 6, presented by Michael Corey and Don Sullivan. This is a must see session if you manage DB infrastructure in any way, so check it out when it hopefully comes out on youtube or VMworld.com. Do prepare yourself to replay it several times over to capture all of the content as attending it was like being hit with a recommendation gatling gun, but the accompanying slide deck should be basic training for all new VMware admins in the field! Michael also provided the quote of the day for today:

Right sizing is everything.


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