In my previous exercise with Heptio Velero, I looked at backing up and restoring a Couchbase deployment. This time I turned my attention to another popular containerized application, Cassandra. Cassandra is a NoSQL database, similar in some respects to Couchbase. Once again, I will be deploying Cassandra as a set of containers and persistent volumes from Kubernetes running on top of PKS, the Pivotal Container Service. And again, just like my last exercise, I will be instantiating the Persistent Volumes as virtual disks on top of vSAN. I’ll show you how to get Cassandra up and running quickly by sharing…
Those of you who work in the cloud native space will probably be aware of VMware’s acquisition of Heptio back in December 2018. Heptio bring much expertise and a number of products to the table, one of which I was very eager to try it. This is the Heptio Velero product, previously known as Heptio Ark. Heptio Velero provides a means to back up and restore cloud native applications. Interestingly enough, they appear to be able to capture all of the deployment details, so they are able to backup the pods (compute), persistent volumes (storage) and services (networking), as well…
At VMworld last year, Duncan Epping and I presented on the power of Storage Policy Based Management (SPBM for short). You can find all of the slides and recordings here. One of the demos we used in the presentation was deploying virtual machines via vRealize Automation, and showing how to consume a storage policy on vSAN. This was using a vRealize Automation plugin, and to be honest, it was a little bit challenging to get it to work. And it wasn’t really a VMware plugin per-se, but something developed by our field team. Today, I’m pleased to announce that we…
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…