After publishing the vSAN Networking Guide earlier this year, Paudie O’Riordain and I received numerous questions regarding support on having different stretched clusters hosting each other’s witness appliances. These queries arose because we discussed a 2-node (ROBO) topology which allowed this to sort of configuration (i.e. the cross hosting of witnesses) via special request. But in the networking guide, we explicitly stated that this was not supported with vSAN stretched clusters. However, after some further testing by our engineering teams, we can now relax this restriction if there are 4 independent sites hosting the different stretched clusters. In this case,…
Now that the US VMworld 2017 event in Las Vegas is over for another year, the focus turns to the VMworld 2017 event in Europe. This year, it once again takes place in Barcelona, Spain. A difference this year is that there is not much of a gap between US and European events, with the Europe event taking place in September this year rather than in October like it usually does. Just like the VMworld Las Vegas event, I am co-presenting on three sessions. In additional to that, in Barcelona, I am also hosting a number of Meet-The-Expert round-tables on…
Earlier yesterday, I had the opportunity to sit in on a VMworld 2017 session delivered by one of my colleagues, Tushar Thole. Tushar presented “Project Hatchway” to the audience, and like the description of this post suggests, this is all about providing VMware persistent storage to containers. In a nutshell, volumes can now be created on VMFS, NFS and on vSAN in the form of VMDKs, and these volumes can now be consumed by containers instantiated within a container host, i.e. a virtual machine. But there have been some interesting new enhancements which Tushar shared with us in the session.
A quick note to let you know that the session that I delivered on day 1 of VMworld 2017 is now available on YouTube. The session is entitled “A Deep Dive into vSphere 6.5 Core Storage Features and Functionality” and I delivered this with Cody Hosterman of Pure Storage. Judging by the feedback, and the number of passing comments I received in the hallways at VMworld over the past 2 days, it seems that this session was very well received indeed. Hope you like it.
VMworld always has lots of new announcements about various VMware products and initiatives. VMworld 2017 is no different. This morning we had the announcement of PKS, the Pivotal Container Service. Yes, that is a K instead of a C in the acronym – this is to highlight the fact that this container service is using Kubernetes. Using a feature called BOSH from Pivotal, customers can provision Kubernetes onto their on-premises vSphere deployments (including VCF – VMware Cloud Foundation). This provisioning capability has its own project name – “Kubo”. Kubo is a joint project between Google and Pivotal which allows for…
Does anyone remember the ATS Miscompare issue? This blog post from 2 years ago might jog your memory. It is basically an issue that arose when we began using ATS, the VAAI Atomic Test and Set primitive, for maintaining the ‘liveness’ of a heartbeat in vSphere 5.5U2. After making this change, a number of customers started to see “ATS Miscompare detected between test and set HB images” messages after upgrading to vSphere 5.5U2 or later. The HB reference in the message is shorthand for heartbeat. In previous releases, we did not use ATS for maintaining the ‘liveness’ of a heartbeat.…
Along with other improvements to VMFS-6, there is also a new block allocation mechanism which aims to reduce lock contention between hosts sharing the same VMFS-6 filesystem. To understand how lock contention could arise, it is important to understand that resources on VMFS are grouped into resource clusters; this is the same for VMFS-6 and earlier versions on VMFS. Resources could be file descriptors, sub-block, file block, pointer blocks, and so on. Historically, we have always tried to allocate different resource clusters to different ESXi hosts, which meant that only VMs running on the same host shared resources within the…