Today the vSAN Deep Dive ebook promo starts for the UK market! Unfortunately, Amazon only allows us to run these promotions in 2 stores, .com and .co.uk. So we scheduled them where possible. Starting today the ebook will be available on .co.uk for 0.99 pounds for a full week! So to be clear, it starts on the 20th of January and ends on the 27th! Pick it up here: https://www.amazon.co.uk/VMware-vSAN-6-7-Deep-Dive-ebook/dp/B07L8CNZ53/. After the 27th the book will return to the normal price. We hope you all will enjoy it.
Amazon allows publishers to create book promotions and I just created one for the vSAN 6.7 U1 Deep Dive ebook. The promotion starts on the 24th of December and will end on the 31st of December. The ebook promotion will be available only on Amazon.com and Amazon.co.uk, as that is where Amazon allows publishers to create these. The price will start as low as 0.99 USD for the ebook in the US and will go up in increments of 1 USD over the course of 10 days, for the UK the price will start at 0.99 Pounds. The paper copy will also drop in price starting today and will return to normal on the 31st of December. (Note, unfortunately for the UK the ebook promo will start on the 20th of January, Amazon doesn’t allow me to schedule it sooner.) The paper copy will be discounted in all Amazon stores worldwide we have dropped the price by over 50%, in other words, for the US market you can pick it up for less than 20 USD, for EMEA it is less than 15 Euro. This should be a great deal to brush up your vSAN skills over the holiday season!
Make sure to pick a copy up using my referral links below:
3 years ago I wrote the following post: Can I still provision VMs when a VSAN Stretched Cluster site has failed? Last week I received a question on this subject, and although officially I am not supposed to work on vSAN in the upcoming three months I figured I could test this in the evening easily within 30 minutes. The question was simple, in my blog I described the failure of the Witness Host, what if a single host fails in one of the two “data” fault domains? What if I want to create a snapshot for instance, will this still work?
So here’s what I tested:
- vSAN Stretched Cluster
- 4+4+1 configuration
- Meaning, 4 hosts in each “data site” and a witness host, for a total of 8 hosts in my vSAN cluster
- Create a VM with cross-site protection and RAID-5 within the location
So I first failed a host in one of the two data sites. When I fail the host, the following is what happens when I create a VM with RAID-1 across sites and RAID-5 within a site:
- Without “Force Provisioning” enabled the creation of the VM fails
- When “Force Provisioning” is enabled the creation of the VM succeeds, the VM is created with a RAID-0 within 1 location
Okay, so this sounds similar to the originally described scenario, in my 2016 blog post, where I failed the witness. vSAN will create a RAID-0 configuration for the VM. When the host returns for duty the RAID-1 across locations and RAID-5 within each location is then automatically created. On top of that, you can snapshot VMs in this scenario, the snapshots will also be created as RAID-0. One thing to mind is that I would recommend removing “force provisioning” from the policy after the failure has been resolved! Below is a screenshot of the component layout of the scenario by the way.
I also retried the witness host down scenario, and in that case, you do not need to use the “force provisioning” option. One more thing to note. The above will only happen when you create a RAID configuration which is impossible to create as a result of the failure. If 1 host fails in a 4+4+1 stretched cluster you would like to create a RAID-1 across sites and a RAID-1 within sites then the VM would be created with the requested RAID configuration, which is demonstrated in the screenshot below.
About 6.5 years ago I wrote this blog post around the future of Software-Defined Storage and if the VSA (virtual storage appliance) is the future for it. Last week at VMworld a customer reminded me of this article. Not because they read the article and pointed me back at it, but because they implemented what I described in this post, almost to the letter.
This customer had an interesting implementation, which kind of resembles the diagram I added to the blog post, note I added a part to the diagram which I originally left out but had mentioned in the blog (yes that is why the diagram looks like it is ancient… it is):
I want to share with you what the customer is doing because there are still plenty of customers that do not realize that this is supported. Note that this is supported by both vSAN as well as VMware Cloud Foundation, providing you a future proof, scalable, and flexible full-stack HCI architecture which does not need to be implemented in a rip and replace approach!
This customer basically leverages almost all functionality of our Software-Defined Storage offering. They have vSAN with locally attached storage devices (all NVMe) for certain workloads. They have storage arrays with vVols enabled for particular workloads. They have a VAIO Filter Driver which they use for replication. They also heavily rely on our APIs for monitoring and reporting, and as you can imagine they are a big believer in Policy-Based Management, as that is what helps them with placing workloads on a particular type of storage.
Now you may ask yourself, why on earth would they have vSAN and vVols sitting next to each other? Well, they had a significant investment in storage already, the storage solution was fully vVols capable and when they started using vSAN for certain projects they simply fell in love with Storage Policy-Based Management and decided to get it enabled for their storage systems as well. Even though the plan is to go all-in on vSAN over time, the interesting part here, in my opinion, is the “openness” of the platform. Want to go all-in on vSAN? Go ahead! Want to have traditional storage next to HCI? Go ahead! Want to use software-based data services? Go ahead! You can mix and match, and it is fully supported.
Anyway, just wanted to share that bit, and figured it would also be fun to bring up this 6.5 years old article again. One more thing, I think it is also good to realize how long these transitions tend to take. If you would have asked me in 2013 when we would see customers using this approach my guess would have been 2-3 years. Almost 6.5 years later we are starting to see this being seriously looked at. Of course, platforms have to mature, but also customers have to get comfortable with the idea. Change simply takes a lot of time.
A while ago I had the pleasure to join David S. Linthicum from GigaOm on their Voices in Cloud Podcast. It is a 22 minute podcast where we discuss various VMware efforts in the cloud space, edge computing and of course HCI. You can find the episode here, where they also have the full transcript for those who prefer to read instead of listen to a guy with a Dutch accent. It was a fun experience for sure, I always enjoy joining podcast’s and talking tech… So if you run a podcast and are looking for a guest, don’t hesitate to reach out!