Kubernetes, Hadoop, Persistent Volumes and vSAN

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…

vSAN 6.7U1 – Capacity History – Unable to query charts data

A very quick heads-up to let you know about an issue some of us experienced with vSAN 6.7U1 and about how to resolve it. We noticed that after upgrading to vSAN 6.7U1, the new Capacity History view did not work. However brand new installs of 6.7U1 worked just fine. The error that one gets from trying to look at the capacity history is “Unable to query charts data for capacity history” as shown below: I’m pleased to report that we have a solution for this issue already. It was caused by an inability to update the database schema in the…

New vSAN 6.7U1 Advanced Options

Most readers will be aware that vSAN version 6.7U1 was recently released. For those of you who wish to know more about the release, I wrote this blog article last month detailing the new features. In this post I want to cover an item which many of you may not be aware of. It is a new feature which makes the most common vSAN advanced options visible and configurable in the vSphere UI. There are 3 advanced options which we have surfaced up. The first is the VSAN.ClomRepairDelay timer which is the delay used before rebuilding ABSENT components. The second…

A closer look at EBS-backed vSAN

At VMworld 2018, we announced an initiative to use EBS, Amazon Elastic Block Store, for vSAN storage. At present vSAN is configured using the current EC2 i3 configurations, which run ESXi on bare-metal. I have seen these referred to as i3p, but my understanding is that they correlate to the i3.metal instances as shown here. The Amazon EC2 i3 instances include Non-Volatile Memory Express (NVMe) SSD-based instance storage. These are configured with 10TB of storage per host, but there are some limitations. For one, if you wish to expand on capacity, you need to add another complete EC2 i3 instance.…

Change policy on a vSAN object via RVC

I had someone reach out to me recently, asking for a way to change the policy on a file that was uploaded to a vSAN datastore, e.g. an ISO image. When a file is uploaded to the vSAN datastore, a VM Home namespace object is created. It is into this ‘file system’ type object that the files/ISOs are stored. Initially, I looked at ways to change the VM Home namespace. I looked at various commands to change the policy and I did find some in RVC, the Ruby vSphere Console. Unfortunately all the spbm.namespace_change commands look for a VM as…

What’s new in vSAN 6.7U1

Yesterday, we saw the announcement that VMware has release vSphere 6.7U1. This includes new releases of vCenter Server 6.7U1, ESXi 6.7U1 and of course vSAN 6.7U1. All of the hyperlinks here will take you to the release notes of that particular product. In this post, I just want to briefly run through some of the major enhancements that we have included in vSAN 6.7U1. TRIM/UNMAP Support Top of the list for me is the introduction of automated UNMAP support. Note that the key point here is that this is for in-guest space reclamation. vSAN has never had an issue with…

iSCSI on vSAN Stretched Cluster

vSAN readers will most likely be aware that we introduced support for iSCSI on vSAN way back in vSAN 6.5. That is to say, we had the ability to create iSCSI targets and LUNs using vSAN objects, and present the LUNs to external iSCSI initiators. That release also supported Persistent Group Reservations (PGRs) but it did lack transparent failover. We followed this up with an enhancement in vSAN 6.7 which enabled transparent failover. This enabled support for features like Windows Server Failover Cluster (WSFC) to work on iSCSI on vSAN, if using shared disk mode as it uses reservations on…