After a bit of a sabbatical, I am back to looking PKS (Pivotal Container Service) again. I wanted to look at the new version 1.3, but I had to do a bit of work on my environment to allow me to do this. Primarily, I needed to upgrade my NSX-T environment from version 2.1 to 2.3. I followed this blog post from vmtechie which provides a useful step-by-step guide. Kudos to our VMware NSX-T team as the upgrade worked without a hitch. My next step was to start work on the PKS deployment. I just did a brand new deployment…
Degraded Device Handling (DDH) or Dying Disk Handling as it was formerly known, is a feature that has been available in vSAN for some time. However, I regularly get questions about how it works. The DDH behavior has changed significantly over various versions. We may as well begin this post with an overview about the purpose of DDH and then get into the different sort of behaviors. First of all, the reason behind a feature such as DDH is to help avoid cluster performance degradation due to an unhealthy drive. In the early days of vSAN, we had come across…
I had a very interesting question recently about how vSAN handles a failure in an object that is running with an erasure coding configuration. In the case of vSAN this is either a RAID-5 or a RAID-6. On vSAN, a RAID-5 is implemented with 3 data segments and 1 parity segment (3+1), with parity striped across all four components. RAID-6 is implemented as 4 data segments and 2 parity segments (4+2), again with the parity striped across all of the six components. Now, on vSAN, RAID-5 requires 4 physical ESXi hosts for implementation, with each host backing one set of…
I am delighted to announce the availability of our newly updated VMware vSAN 6.7U1 Deep Dive book. This is the 3rd edition of the book. As the title states, this book’s content has been updated to include information about the latest version of vSAN, which is of course 6.7U1. Much thanks to my good friend and co-author, Duncan Epping. As well as doing his share of the content, Duncan took care of all of the admin to get the book available online, something I have no clue about. Thanks man! Also a great big shout out to both Pete Koehler…
Some time back, nearly 6 years ago in fact, I wrote about how you might hit the NFS maximum value for the number of connections you can have per IP address when mounting a lot of shares from the same NFS target. You can find the article in question here. The question came up again recently, and I found that a few things have changed since I wrote that post. In this updated post, thanks to some feedback from our NFS engineers, I wanted to revisit this scenario and explain in some further detail what the limits are. First of…
At VMworld 2018, one of the sessions I presented on was running Kubernetes on vSphere, and specifically using vSAN for persistent storage. In that presentation (which you can find here), I used Hadoop as a specific example, primarily because there are a number of moving parts to Hadoop. For example, there is the concept of Namenode and a Datanode. Put simply, a Namenode provides the lookup for blocks, whereas Datanodes store the actual blocks of data. Namenodes can be configured in a HA pair with a standby Namenode, but this requires a lot more configuration and resources, and introduces additional…
After just deploying the newest version of Pivotal Container Services (PKS) and rolling out my first Kubernetes cluster (read all about it here), I wanted to try to do something a bit more interesting than just create another persistent volume claim to test out our vSphere Cloud Provider since I had done this a number of times already. Thanks to some of the work I have been doing with our cloud native team, I was introduced to StatefulSets. That peaked my interest a little, as I had not come across them before.