A very short post simply to bring an issue to your attention which a number of folks have pinged me about this week. With vSAN 6.6, there is a new feature called Configuration Assistant. As the name implies, it tries to highlight possible configuration issues with your vSAN infrastructure. A number of these checks are related to network configuration. Configuration Assistant checks to make sure that the vSAN network has availability by verifying that there are 2 or more physical NICs. For example, let me show you my setup. Here is my vSAN vmkernel port, and as you can see,…
I was looking into some behavior recently to assist one of our partners. He described a situation that they observed during proof-of-concept testing. I thought it would be of benefit to highlight this behavior in case you also observe it, and you are curious as to why it is happening. Let’s begin with a description of the test. The customer has a 7-node vSAN, and has implemented RAID-6 erasure coding for all VMs across the board. The customer isolated one host, and as expected, the VMs continued to run without issue. The customer was also able to clones virtual machine…
vSphere 6.5 saw the release of a number of improvements in the areas of DRS. I won’t detail all of the improvements here, since my colleague Brian Graf has done a great job of describing the features in a number of different blog posts. He discussed Network-Aware DRS here, Predictive DRS here and Proactive HA here. Instead, what I wanted to talk about in this post is how these features inter-operate with vSAN, if they do at all. I’ve been asked this question a few times now, so after reaching out to Brian and a number of resources on this…
I’m delighted to report that I’ve been invited to speak at the upcoming Norway VMUG (VMware User Group) meetings. These take place in three different cities over the week of May 29th (week 22), with three meetings in three days. On Tuesday, May 30th, the Oslo VMUG will take place. On May 31st, it’s the turn of the Trondheim VMUG and we will finish with the Bergen VMUG on June 1st. I am going to broaden the scope of the conversation at these VMUGs, and talk about Storage Policy Based Management (SPBM) in general. Of course, we will look at…
Last week, I had a chance to catch up with my pal, Rawlinson Rivera. Rawlinson and I worked closely on a lot of storage related stuff at VMware, but he has since moved on to pastures new, and is currently the CTO for the Global Field over at Cohesity. I’ve written about Cohesity a number of times on this blog. I think the first time I wrote about them was during VMworld 2015, just before the 1.0 product launched, and they were still pitching the idea of secondary storage and how they would take care of things like snaps, clones,…
I was looking at the layout of RAID-5 object configuration the other day, and while these objects were deployed on vSAN with 4 components, something caught my eye. It wasn’t the fact that there were 4 components, which is what one would expect since we implement RAID-5 as a 3+1, i.e. 3 data segments and 1 parity segment. No, what caught my eye was that one of the components had a different vote count. Now, RAID-5 and RAID-6 erasure coding configurations are not the same as RAID-1. With RAID-1, we deploy multiple copies of the data depending on how many…
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.