Cloning and Snapshots on vSAN when policy requirements cannot be met

I was looking into some behavior recently to assist one of our partners. He described a situation that they observed during proof-of-concept testing. I thought it would be of benefit to highlight this behavior in case you also observe it, and you are curious as to why it is happening. Let’s begin with a description of the test. The customer has a 7-node vSAN, and has implemented RAID-6 erasure coding for all VMs across the board. The customer isolated one host, and as expected, the VMs continued to run without issue. The customer was also able to clones virtual machine…

A closer look at Cohesity 4.0

Last week, I had a chance to catch up with my pal, Rawlinson Rivera. Rawlinson and I worked closely on a lot of storage related stuff at VMware, but he has since moved on to pastures new, and is currently the CTO for the Global Field over at Cohesity. I’ve written about Cohesity a number of times on this blog. I think the first time I wrote about them was during VMworld 2015, just before the 1.0 product launched, and they were still pitching the idea of secondary storage and how they would take care of things like snaps, clones,…

Virtually Speaking Podcast Episode #34 – Core Storage

Many readers will be aware that John Nicholson and Pete Fletcha of the VMware Storage and Availability Tech Marketing team run a weekly podcast show called  Virtually Speaking. This week I am back as a guest on their show, alongside Cody Hosterman of Pure Storage. We discuss a lot of the new core storage features in vSphere 6.5, which were detailed in a co-produced white paper that we recently created. You can read about how to get the white paper here. You can listen to the podcast through the player below. I hope you enjoy it.

Some highlights from VMworld 2016

With Virtual SAN gaining huge momentum, I had a pretty busy VMworld 2016 in Las Vegas, and I didn’t have too much free time this year to immerse myself in the Solutions Exchange. However there were a few folks that I did want to catch up with as I had heard that they have some cool new features added to their product sets. So I made a bee-line to check them out. Let me know if you found anything else interesting. I might have a little more time in VMworld Barcelona to check out the solutions exchange and see what…

A primer on App Volumes and AppStacks on VSAN

Last week I wrote a post on Horizon View 7 on VSAN. That was all about showing the policies that were associated with the different desktops that can be deployed. I did mention that while one could use vmFork/Instant Clones for desktops, they did not include any sort of persistence. I did add a caveat to say that you could provide persistent storage to these desktops using App Volumes. In this post, I wanted to give some details on App Volumes, and the different moving components one will need if they want to deploy View desktops with App Volumes. However,…

Snapshot Consolidation changes in vSphere 6.0

This is something I only learnt about very recently, and something I was unaware of. It seems that we have made a major improvement to the way we do snapshot consolidation in vSphere 6.0. Many of you will be aware of the fact that when they VM is very busy, snapshot consolidation may need to go through multiple iterations before we can successfully complete the consolidation/roll-up operation. In fact, there are situations where the snapshot consolidation operation could even fail if there is too much I/O. What we did previously is used a helper snapshot, and redirected all the new…

I/O Scheduler Queues Improvement for Virtual Machines

This is a new feature in vSphere 6.0 that I only recently became aware of. Prior to vSphere 6.0, all the I/Os from a given virtual machine to a particular device would share a single I/O queue. This would result in all the I/Os from the VM (boot VMDK, data VMDK, snapshot delta) queued into a single per-VM, per-device queue. This caused I/Os from different VMDKs interfere with each other and could actually hurt fairness. For example, if a VMDK was used by a database, and this database issued a lot of I/O, this could compete with I/Os from the…