Sizing for large VMDKs on vSAN

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.

vSphere 6.5 p01 – Important patch for users of Automated UNMAP

VMware has just announced the release of vSphere 6.5 p01 (Patch ESXi-6.5.0-20170304001-standard). While there are a number of different issues addressed in the patch, there is one in particular that I wanted to bring to your attention. Automated UNMAP is a feature that we introduced in vSphere 6.5. This patch contains a fix for some odd behaviour seen with the new Automated UNMAP feature. The issue has only been observed with certain Guest OS, certain filesystems, and a certain block sizes format. KB article 2148987 for the patch describes it as follows: Tools in guest operating system might send unmap…

2-node vSAN topologies review

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…

A closer look at Runecast

Last week, I had the pleasure of catching up with a new startup called Runecast. These guys are doing something that is very close to my heart. As systems become more and more complex, and with fewer people taking on more responsibility, highlighting potential issues, and providing descriptive guidance to resolving an issue is now critical. This is something that is resonating in the world of HCI, hyper-converged infrastructure, where the vSphere administrator may also be the storage administrator, and perhaps the network administrator too. This is where Runecast come in. Using a myriad of resources such as VMware’s Knowledgebase…

Getting More Out of vSAN – Webcast Series coming to EMEA

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.…

vSphere 6.0 Update 3 – Important Update for vSAN

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…

Kubernetes on vSphere with kubernetes-anywhere

I already described how you can get started with Kubernetes natively on vSphere using the kube-up/kube-down mechanism. This was pretty straight-forward, but not ideal as it was not very reliable or easy to follow. Since writing that piece, Kubernetes have moved on to a new deployment mechanism called kubernetes-anywhere. In this post, I will show you how to deploy Kubernetes onto a vSphere environment with a vSAN datastore, using the kubernetes-anywhere utility. All of this is done from a Photon OS VM. Now in my previous example, I used the Photon OS OVA, which is a trimmed down version  of…