Search Results for: vsan 6.2

Can you run all-flash with vSAN 6.2 Standard license?

Duncan Epping · Jan 15, 2017 ·

As I get the following question a lot I figured I would share the answer here as well: Can you run all-flash with vSAN 6.2 Standard license? Many of you have seen the change in licensing when 6.5 was introduced. No longer is vSAN licenses based on storage hardware used, spindles or all-flash, you can use the lowest license SKU. Which of course is great for those wanting to use 6.5, but what about those who want to stick to 6.0 U2 aka vSAN 6.2? (This also works for 6.0 and 6.1 of course, but I would highly recommend 6.2 with the latest patches!)

Well there is a way to “downgrade” your license. (I would call it convert myself, but downgrade apparently is the official term for it.) There are 3 simple steps which are described in the following KB, but copied/pasted here for your convenience:

Navigate to and login in to your MyVMware portal at www.myvmware.com.
Locate the page with your licenses, and then select the license to convert. Once selected, click “Downgrade License Keys” from the drop down menu.
Two downgrade options will be displayed in another drop down menu. Select “Virtual SAN 6 with All Flash Add-on” to convert your existing vSAN STD licenses to a STD version that includes the all-flash add-on.

VSAN 6.2, checksumming where you should

Duncan Epping · Mar 24, 2016 ·

Today I was talking to a customer about the checksum functionality that is part of VSAN 6.2. They asked me if VSAN was still prone to bit rot scenarios, and they mentioned other potential bottlenecks like no data locality… It was fairly straight forward to set it straight as with VSAN 6.2 we do have a “host local read cache” and we checksum all data by default on write and on read, and yes we also scrub the disk to pro-actively detect potential issues. I’ve already written about these features a couple of times, but today when explaining to this customer how VSAN’s checksumming functionality is implemented the customer immediately realized the benefits of our hypervisor based implementation. Note that the diagram below shows the VM running on a different host then where the actual data is located, the VM could easily be running on the same host as where one of the replicas is located…

When it comes to checksums, these are calculated on the host where the VM resides. Why? Well you can imagine that you will want to protect your data against all types of potential corruption and issues. Not just when at rest, but you want to calculate the checksum before the data leaves the host, before it is replicated / distributed, before it hits the disk controller, before it goes to persistent media! Even if a bit flips while traveling across the network to be written to persistent media this will be detected and corrected.That is exactly what VSAN does, which is unique. As the title says, checksumming where you should… at the source.

Want to hear all about VSAN 6.2? Watch the #SFD9 recordings!

Duncan Epping · Mar 20, 2016 ·

Last week my colleagues had the pleasure to present at Storage Field Day 9 (SFD9). The topic was Virtual SAN, and more specifically what we released with 6.2 and how we are doing from a business point of view / where we stand in the industry. Great explanation by the team on all the different aspects of this release, and even around some of the basic constructs like disk groups etc. One thing that stood out to me, was the explanation of Yanbing around the customer count, I’ve seen one of our competitors screaming shelfware every time they get the chance, which I guess is a great validation to begin with because why worry about something that isn’t a problem to begin with, but still I would like to share this quote:

VSAN has well over 3000 customers. So how did we count these 3000 customers. VSAN’s business is largely build on a transaction based business. Three quarters (75%) of the customers come from the transaction deals. Another quarter (25%) comes from ELA (enterprise license agreements), and most of those customers go through a Proof of Concept with VSAN and they have decided to make that choice. We also have another customer segment which is through the Horizon / VDI use case where we track actual deployments in those use cases.

The intro is by Yanbing Li, General Manager of the Storage and Availability business unit at VMware. Followed by the basics, what’s new and deeper dives by Christos Karamanolis, CTO Storage and Availability at VMware. And last a short demo to show the operational simplicity by Rawlinson Rivera, Principal Architect Storage and Availability at VMware. I created a simple playlist, if you want to skip videos you can do so by clicking those lines top left and select the one you want to view. Thanks Stephen Foskett for capturing and sharing these sessions, awesome job once again!

Here you go, VSAN 6.2 GA!

Duncan Epping · Mar 16, 2016 ·

We’ve been talking about if for a while now, but last night the moment finally arrived… VSAN 6.2 aka vSphere 6.0 Update 2 was released. I am not going to go in to any level of depth here, as I have written many posts on the subject of VSAN 6.2 already, and so has my friend Cormac, the best start is probably this blog though. You can read those if you want to get the nitty gritty details, or nerd knobs as apparently some like to call it. (I prefer to call it a healthy level of curiosity, but that is a different discussion.) Here is what is in 6.2:

Deduplication and Compression
RAID-5/6 (Erasure Coding)
Sparse Swap Files
Checksum / disk scrubbing
Quality of Service / Limits
In mem read caching
Integrated Performance Metrics
Enhanced Health Service

Now that is not it, there is also some new stuff in vSphere 6.0 Update 2, one which I feel is very welcome and that is the Host Client! A full HTML5 based client which comes as part of your ESXi host, very useful if you ask me! Also two-factor authentication was added for the Web Client, several enhancements to the vSphere APIs for IO Filtering and support for different databases for vCenter etc.

Okay, lets stop blabbing, start your download engines, find your bits here:

ESXi 6.0 U2 – Release Notes
vCenter Server 6.0 U2 – Release Notes

VSAN 6.2 : Why going forward FTT=2 should be your new default

Duncan Epping · Mar 1, 2016 ·

I’ve been talking to a lot of customers the past 12-18 months, if one thing stood out is that about 98% of all our customers used Failures To Tolerate = 1. This means that 1 host or disk could die/disappear without losing data. Most of the customers when talking to them about availability indicated that they would prefer to use FTT=2 but cost was simply too high.

With VSAN 6.2 all of this will change. Today with a 100GB disk FTT=1 results in 200GB of required disk capacity. With FTT=2 you will require 300GB of disk capacity for the same virtual machine, which is an extra 50% capacity required compared to FTT=1. The risk, for most people, did not appear to weigh up against the cost. With RAID-5 and RAID-6 the math changes, and the cost of extra availability also changes.

The 100GB disk we just mentioned with FTT=1 and the Failure Tolerance Method set to “RAID-5/6” (only available for all flash) means that the 100GB disk requires 133GB of capacity. Already that is a saving of 67GB compared to “RAID-1”. But that savings is even bigger when going to FTT=2, now that 100GB disk requires 150GB of disk capacity. This is less than “FTT=1” with “RAID-1” today and literally half of FTT=2 and FTM=RAID-1. On top of that, the delta between FTT=1 and FTT=2 is also tiny, for an additional 17GB disk space you can now tolerate 2 failures. Lets put that in to a table, so it is a bit easier to digest. (Note that you can sort the table by clicking on a column header.)

FTT	FTM	Overhead	VM size	Capacity required
1	Raid-1	2x	100GB	200GB
1	Raid-5/6	1.33x	100GB	133GB
2	Raid-1	3x	100GB	300GB
2	Raid-5/6	1.5x	100GB	150GB

Of course you need to ask yourself if your workload requires it, does it make sense with desktops? Well for most desktops it probably doesn’t… But for your Exchange environment maybe it does, for your databases maybe it does, for your file servers, print servers, for your web farm even it can make a difference. That is why I feel that the standard used “FTT” setting is going to change slowly, and will (should) be FTT=2 in combination with FTM set to “RAID-5/6”. Now let it be clear, there is a performance difference between FTT=2 with FTM=RAID-1 vs FTT=2 with FTM=RAID-6 (same applies for FTT=1) and of course there is a CPU resource cost as well. Make sure to benchmark what the “cost” is for your environment and make an educated decision based on that. I believe though that in the majority of cases the extra availability will outweigh the cost / overhead, but still this is up to you to determine and decide. What is great about VSAN in my opinion is the fact that we offer you the flexibility to decide per workload what makes sense.