Sorry about the wordy title but this is a question that has come up a number of times. The request is that when I have two data sites and deploy two stretched clusters across these data sites, can the other stretched cluster support the witness appliance for this stretched cluster, and vice-versa? The answer is no, and I will explain why in this post.
vSAN 6.6 is finally here. This sixth iteration of vSAN is the quite a significant release for many reasons, as you will read about shortly. In my opinion, this may be the vSAN release with the most amount of new features. Let’s cut straight to the chase and highlight all the features of this next version of vSAN. There is a lot to tell you about. Now might be a good time to grab yourself a cup of coffee.
I recently noticed a blog post describing some very strange behaviors in 2-node and 3-node vSAN clusters. I was especially concerned to read that when they introduced a failure and then fixed that failure, they did not experience any auto-recovery. I have reached out to the authors of the post, just to check out some things such as version of vSAN, type of failure, etc. Unfortunately I haven’t had a response as yet, but I did feel compelled to put the record straight. In the following post, I am going to introduce a variety of operations and failures in my…
I’ve recently been involved in some design and sizing for very large VMDKs on vSAN. There are a couple of things to keep in mind when doing this, not just the overhead when deciding to go with RAID1, RAID5 or RAID6, but also what this means for component counts. In the following post, I have done a few tests with some rather large RAID-5 and RAID-6 VMDKs, just to show you how we deal with it in vSAN. If you are involved in designing and sizing vSANs for large virtual machines, you might find this interesting.
There has been a lot of discussion in the past around supported topologies for 2-node vSAN, specifically around where we can host the witness. Now my good pal Duncan has already highlighted some of this in his blog post here, but the questions continue to come up about where I can, and where I cannot place the witness for a 2-node vSAN deployment. I also want to highlight that many of these configuration considerations are covered by our official documentation. For example, there is the very comprehensive VMware Virtual SAN 6.2 for Remote Office and Branch Office Deployment Reference Architecture…
Earlier this year, our colleagues in the US kicked off the “Getting More Out of vSAN” webcast series. We are pleased to be able to replicate this initiative in EMEA. We now have 2 webcast sessions lined up for the month of March: Session 1: vSAN Architecture & Tips and Tricks for 6.5, 14 March @ 10AM GMT This session provides an overview of vSAN’s architecture, policy based management and commonly used terms. We will also examine vSAN 2-node and stretched cluster configurations and some popular vSAN use cases. We will finish with an overview of new vSAN 6.5 features.…
ESXi 6.0 Update 3 is now available. This update is significant for vSAN customers as there are a number of performance related issues addressed. The KB article detailing vSAN performance improvements can be found here, and the ESXi 6.0 U3 release notes can be found here. I wouldn’t necessarily write a blog post to highlight a KB or update release, but I think the improvements that have been made to vSAN performance in this update are very significant. Improvements include enhancements to the way that we do logging. In vSAN, every I/O operation is logged before being processed. We have…