I recently had the opportunity to run through a VMware Cloud on Disaster Recovery deployment with a customer and thought I’d run through the basics. It’s important to note that there a variety of topologies supported with VCDR, and many things that need to be considered before you click deploy, and this is just one way of doing it. In any case, there’s a new document outlining the process on the articles page.
Happy New Year (to those who celebrate). Let’s get random.
In this edition of Things My Customers Have Asked Me (TMCHAM), I’m going to delve into some questions around TRIM/UNMAP and capacity reclamation on the VMware-managed VMware Cloud on AWS platform.
Why TRIM/UNMAP?
TRIM/UNMAP, in short, is the capability for operating systems to reclaim no longer used space on thin-provisioned filesystems. Why is this important? Imagine you have a thin-provisioned volume that has 100GB of capacity allocated to it. It consumes maybe 1GB when it’s first deployed. You then add 50GB of data to it. You then delete 50GB of data from the volume. You’ll still see 51GB of capacity being consumed on the filesystem. This is because older operating systems just mark the blocks as deleted, but don’t zero them out. Modern operating systems do support TRIM/UNMAP though, but the hypervisor needs to understand the commands being sent to it. You can read more on that here.
How I Do This For VMware Cloud on AWS?
You can contact your account team, and we raise a ticket to get the feature enabled. We had some minor issues recently that meant we weren’t enabling the feature, but if you’re running M16v12 or M18v5 (or above) on your SDDCs, you should be good to go. Note that this feature is enabled on a per-cluster basis, and you need to reboot the VMs in the cluster for it to take effect.
What About Migrating With HCX?
Do the VMs come across thin? Do you need to reclaim space first? If you’re using HCX to go from thick to thin, you should be fine. If you’re migrating thin to thin, it’s worth checking whether you’ve got any space reclamation in place on your source side. I’ve had customers report back that some environments have migrated across with higher than expected storage usage due to a lack of space reclamation happening on the source storage environment. You can use something like Live Optics to report on your capacity consumed vs allocated, and how much capacity can be reclaimed.
Why Isn’t This Enabled By Default?
I don’t know for sure, but I imagine it has something to do with the fact that TRIM/UNMAP has the potential to have a performance impact from a latency perspective, depending on the workloads running in the environment, and the amount of capacity being reclaimed at any given time. We recommend that you “schedule large space reclamation jobs during off-peak hours to reduce any potential impact”. Given that VMware Cloud on AWS is a fully-managed service, I imagine we want to control as many of the performance variables as possible to ensure our customers enjoy a reliable and stable platform. That said, TRIM/UNMAP is a really useful feature, and you should look at getting it enabled if you’re concerned about the potential for wasted capacity in your SDDC.
Welcome to Random Short Take #78. We’re hurtling towards the silly season. Let’s get random.
At VMware Explore 2022 in the US, VMware announced a number of new offerings for VMware Cloud on AWS, including a new bare-metal instance type: the I4i.metal. You can read the official blog post here. I thought it would be useful to provide some high-level details and cover some of the caveats that punters should be aware of.
By The Numbers
Other Regions will have availability over the coming months.
Thoughts
The i3.metal isn’t going anywhere, but it’s nice to have an option that supports more cores and it a bit more storage and RAM. The I4i.metal is great for SQL workloads and VDI deployments where core count can really make a difference. Coupled with the addition of supplemental storage via VMware Cloud Flex Storage and Amazon FSx for NetApp ONTAP, there are some great options available to deal with the variety of workloads customers are looking to deploy on VMware Cloud on AWS.
On another note, if you want to hear more about all the cloudy news from VMware Explore US, I’ll be presenting at the Brisbane VMUG meeting on October 12th, and my colleague Ray will be doing something in Sydney on October 19th. If you’re in the area, come along.
The October 2022 edition of the Brisbane VMUG meeting will be held on Wednesday 12th October at the Cube (QUT) from 5pm – 7pm. It’s sponsored by NetApp and promises to be a great afternoon.
Two’s Company, Three’s a Cloud – NetApp, VMware and AWS
NetApp has had a strategic relationship with VMware for over 20 years, and with AWS for over 10 years. Recently at VMware Explore we made a significant announcement about VMC support for NFS Datastores provided by the AWS FSx for NetApp ONTAP service.
Come and learn about this exciting announcement and more on the benefits of NetApp with VMware Cloud. We will discuss architecture concepts, use cases and cover topics such as migration, data protection and disaster recovery as well as Hybrid Cloud configurations.
There will be a lucky door prize as well as a prize for best question on the night. Looking forward to see you there!
Wade Juppenlatz – Specialist Systems Engineer – QLD/NT
Chris (Gonzo) Gondek – Partner Technical Lead QLD/NT
PIZZA AND NETWORKING BREAK!
This will be followed by:
All the News from VMware Explore – (without the jet lag)
We will cover a variety of cloudy announcements from VMware Explore, including:
Dan Frith – Staff Solutions Architect – VMware Cloud on AWS, VMware
And we will be finishing off with:
Preparing for VMware Certifications
With the increase of position requirements in the last few years, certifications help you demonstrate your skills and move you a step forward on getting better jobs. In this Community Ssession we will help you understand how to prepare for a VMware certification exam and some useful tips you can use during the exam.
We will talk about:
Francisco Fernandez Cardarelli – Senior Consultant (4 x VCIX)
Soft drinks and vBeers will be available throughout the evening! We look forward to seeing you there!
Doors open at 5pm. Please make your way to The Atrium, on Level 6.
You can find out more information and register for the event here. I hope to see you there. Also, if you’re interested in sponsoring one of these events, please get in touch with me and I can help make it happen.
At VMware Explore 2022 in the US, VMware announced a number of new offerings for VMware Cloud on AWS, including something we’re calling “Supplemental Storage”. There are some great (official) posts that have already been published, so I won’t go through everything here. I thought it would be useful to provide some high-level details and cover some of the caveats that punters should be aware of.
The Problem
VMware Cloud on AWS has been around for just over 5 years now, and in that time it’s proven to be a popular platform for a variety of workloads, industry verticals, and organisations of all different sizes. However, one of the challenges that a hyper-converged architecture presents is that resource growth is generally linear (depending on the types of nodes you have available). In the case of VMware Cloud on AWS, we (now) have 3 node types available for use: the I3, I3en, and I4i. Each of these instances provides a fixed amount of CPU, RAM, and vSAN storage for use within your VMC cluster. So when your storage grows past a certain threshold (80%), you need to add an additional node. This is a longwinded way of saying that, even if you don’t need the additional CPU and RAM, you need to add it anyway. To address this challenge, VMware now offers what’s called “Supplemental Storage” for VMware Cloud on AWS. This is ostensibly external datastores presented to the VMC hosts over NFS. This comes in two flavours: FSx for NetApp ONTAP and VMware Cloud Flex Storage. I’ll cover this in a little more detail below.
[image courtesy of VMware]
Amazon FSx for NetApp ONTAP
The first cab off the rank is Amazon FSx for NetApp ONTAP (or FSxN to its friends). This one is ONTAP-like storage made available to your VMC environment as a native service. It’s fully customer managed, and VMware managed from a networking perspective.
[image courtesy of VMware]
There’s a 99.99% Availability SLA attached to the service. It’s based on NetApp ONTAP, and offers support for:
The other option for supplemental storage is VMware Cloud Flex Storage (sometimes referred to as VMC-FS). This is a datastore presented to your hosts over NFSv3.
Overview
VMware Cloud Flex Storage is:
In short, VMware has taken a lot of the technology used in VMware Cloud Disaster Recovery (the result of the Datrium acquisition in 2020) and used it to deliver up to 400 TiB of storage per SDDC.
Welcome to Random Short Take #75. Half the year has passed us by already. Let’s get random.
In this edition of Things My Customers Have Asked Me (TMCHAM), I’m going to delve into some questions around managing host additions and failures on the VMware-managed VMware Cloud on AWS platform.
Elastic DRS
One of the questions I frequently get asked by customers is what happens when you reach a certain capacity in your VMware Cloud on AWS cluster? The good news is we have a feature called Elastic DRS that can take care of that for you. Elastic DRS is a little different to what you might know as the vSphere Distributed Resource Scheduler (DRS). Elastic DRS operates at a host level and takes care of capacity constraints in your VMC environment. The idea is that, when your cluster reaches a certain resource threshold (be it storage, vCPU, or RAM), Elastic DRS takes care of adding in additional host resources as required.
The algorithm runs every 5 minutes and uses the following parameters:
Note also that your cluster may scale back in, assuming the resources stay consistently below the threshold for a number of iterations.
Settings
There are a few different options for Elastic DRS, with the default being the “Elastic DRS Baseline Policy”. With this policy, a host is automatically added when there’s less than 20% free vSAN storage. Note that this doesn’t apply to single-node SDDC configurations, and only the baseline policy is available with 2-node configurations. Beyond those limitations, though, there are a number of other configurations available and these are outlined here. The neat thing is that there’s some amount of flexibility in how you have your SDDC automatically managed, with options for best performance, lowest cost, or rapid scale-out also available.
Can I Turn It Off?
No, but you can fiddle with the settings from your VMC cloud console.
Other Questions
What happens if I’m adding a host manually? The Elastic DRS recommendations are ignored. Same goes with planned maintenance or SDDC maintenance, where the support team may be adding in an additional host. But what if you’ve lost a host? The auto-remediation process kicks in and the Elastic DRS recommendations are ignored while the failed host is being replaced. You can read more about that process here.
Thoughts
One of the things I like about the VMware Cloud on AWS approach is that VMware has looked into a number of common scenarios that occur in the wild (hosts running out of capacity, for example) and built some automation on top of an already streamlined SDDC stack. Elastic DRS and the Auto-Scaler features seem like minor things, but when you’re managing an SDDC of any significant scale, it’s nice to have the little things taken care of.
Welcome to Random Short Take #74. Let’s get random.