Tag Archive for RDs

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:
http://tekhead.it/blog/2016/02/amazon-aws-tips-and-gotchas-part-1/

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 2014 – Day Three Roundup and Closing Thoughts

Well that’s it, its all over! Having never been to a VMworld prior to this week, I have to say the event does indeed live up to the hype!

Day Three
Day three started pretty subdued, not only from the point of view of the attendees, but a couple of the presenters as well; it definitely seems people had a good time at the VMworld party the night before!

Mixing in a bit of session time with a visit to the solution exchange and a bit of Hands on Labbing was the order of the day. I did have a quite amusing chat with one of the guys working on the Oracle stand. He said that the vast majority of people who had spoken to him had berated them about licensing and support in virtual environments, along with asking why they were advertising OVM at a VMware event. I think the poor guy was not far from the end of his tether!

My last role was at Oracle, so I can fully feel the pain around the license questions as it was almost always the first thing people asked me about when I told them I worked there! It doesn’t help the fact that the latest licensing hard vs soft partitioning guide is still only from 2011!

Oracle Tastiness!

Oracle Tastiness!

One thing I will be very interested to see is what becomes the defacto stance on how many hosts you must license once share-nothing VMotion between clusters, vCenters and DCs comes along in vSphere 6. It begs the question whether any Oracle auditor might have the audacity to suggest that you need to license all hosts in all DCs?

This of course assumes that the specific auditor will not accept mandatory cluster affinity as per Richard’s comments here: http://www.licenseconsulting.eu/vmworld-tv-oracle-on-licensing-vmware-virtualized-environments-updated/

Hopefully in this scenario, common sense would prevail, but that’s deep enough down that rabbit hole for now! 🙂

The sessions I managed to attend on day 3 were as follows:

STO2521 – VSAN Best Practices
Rawlinson Rivera & Kiran Madnani provided a very useful overview of a number of example use cases and how to apply different VSAN configurations. As this was covering multiple use cases there was some repetition of content, but not so far as to be distracting. Key takeaway, when it comes to disk groups, more = better!

VSAN Use Cases

VSAN Use Cases

STO2496 – Storage Best Practices for Next-Gen Storage Platforms
Being a bit of a storage geek, for me this was one of the best sessions of the entire week. Not only entertaining, but the quantity and quality of the information was intense to say the least! A couple of key areas which they covered were around benchmarking of storage (not just using the standard 4k 100% Read profiles which vendors use to produce stats for their marketing material).

Absurd Testing at the Chad & Vaughn Show

Absurd Testing at the Chad & Vaughn Show

TEX1985 – Lessons Learned from a Real Life VSAN POC at Trend Micro
It’s always interesting to see how real customers found the use of a technology. Arsenio Mateos from Trend Micro was not particularly detailed in any specific issues they experienced, as he concentrated more on the decisions behind the solution, and the benefits it broupght them.  Cormac on the other hand was very open and when into some detail as to some of the configuration issues and bugs which were common among other customer deployments. I was also the grateful recipient of a signed copy of the book Cormac co-wrote with Duncan Epping.

EUC2027 – Characterise Performance in Horizon 6
My final session rounded out the end of the day. I don’t currently use or design VMware Horizon View in my current role, when most commonly customers have managed RDS or Citrix XenApp farms. I mainly went to the session to see the VMware approach to sizing the new session host desktops on Horizon 6. Unsurprisingly it turns out that they come out with very similar ratios and guidelines as Citrix do (shocking)!  The really interesting takeaway for me from this session was the VMware View Planner tool, which looked like it could definitely have some value in load testing and gauging the requirements for customers with or without VMware View.

By this time it was 4.30, and everything had closed. If I’m honest I was a bit gutted as I had believed the HoLs were going to be open until 6. I was most of the way through my NSX lab, so I guess I’ll just have to finish it up from home!

After the event, my remaining colleagues and I wandered into town to check out the Sagrada Familia, and grab some light refreshments + tasty tapas.

Sagrada Familia

Sagrada Familia

Wrapping Up
Session Surveys – The one thing I didn’t actually get done at the show (but I plan to fill in this weekend), was the session surveys. I understand these are as valuable to the speakers as to VMware, so I have no issues spending a bit of time giving feedback. If you haven’t already, then I suggest you do, especially if you want to see the same guys & gals back next year!

If I were to be able to make any suggestions to VMware for next year they would be few and far between:

  • Keep the hang space and hands on labs and/or solution exchange open until 6pm on day 3. It’s minimal extra effort but it will allow attendees to make the absolute most of the event and facilities, especially those who don’t have an early flight back the same day.
  • Make the information on getting to the event a bit easier to find on the VMworld.com site (rather than burying it in the FAQs)
  • Free Segways or (or foot massages) for all attendees!

I enjoyed a wander or two around the solution hall, but for me the best and most useful elements of the entire week were the breakout sessions (and being there live giving me the opportunity to ask questions at the end), and networking with others both in the event and at the vendor sponsored evenings.

As a side note, I will probably be creating PDFs of all of my notes and posting these on the blog imminently for anyone who may find them useful.

So finally a big thank you to everyone who made VMworld a success; the organisers, the vendors, the speakers, the HoL team and all of the people with whom I had the such interesting and entertaining discussions!

Key Stats
Number of days attended4 (including partner day)
Blog articles published6
Blogs word count
6,516
Live breakout / HoL sessions attended14
Total session notes word count10,412
Average notes word count per session743
Hands on Labs Completed2
Number of steps walkedNo idea as I don’t have a Fitbit!
Total hours slept in 4 nights< 24
Contacts madeMany
Knowledge gainedIncalculable
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