I posted a few months back about ESXi queue depth limits and how it affects performance. Just recently, Pure Storage announced our upcoming support for vSphere Virtual Volumes. So, this begs the question, what changes with VVols when it comes to queuing? In a certain view, a lot. But conceptually, actually very little. Let’s dig into this a bit more.
This is a blog post I have been waiting to write for quite some time. I cannot even remember exactly how long ago I saw Satyam Vaghani present on this as a concept at VMworld. Back when the concept of what is now called a protocol endpoint (more on that later) was called an I/O Demultiplexer. A mouthful for sure. Finally it’s time! With pleasure, I’d like to introduce VVols on the FlashArray!
So over the past two years or so I have been talking up vRealize Orchestrator quite a bit. And a fair amount of that conversation was based on the eventual usage of vRealize Automation. While I certainly feel vRA is a GREAT use case for vRO, the usefulness of vRO does not in any way require vRA.
A common question I get is, “hey can you add this feature to the official FlashArray Plugin?”. The answer is often “maybe” or “eventually” but sometimes even “no”. The plugin is centered at the satisfying the majority and therefore sometimes does not exactly meet your requirements.
So with these two things in mind, what is the connection? Well, using vRO (which is FREE when you have vCenter) you can easily build your own. Especially when you install the FlashArray vRO plugin.
I see a couple advantages here:
- Start learning vRO. Using default workflows so you don’t have to “code” anything. Then start with some more customization as you become familiar.
- Provide tailored workflows in the vSphere Web Client
- Interface-agnostic workflows. As you move forward and use the HTML-5 interface, or vRA you don’t have to redo your work.
A customer pinged me the other day and said they could not see a volume on their ESXi host. Running ESXi version 6.5. All of the normal stuff checked out, but the volume was nowhere to be seen. What gives? Well it turned out to be the LUN ID was over 255 and ESXi couldn’t see it. Let me explain.
The TLDR is ESXi does not support LUN IDs above 255 for your average device.
*It’s not actually aliens, it is perfectly normal SCSI you silly man.
This is all very exciting for me, finally able to really start blogging about VVols in earnest. As you may or may not be aware we (Pure Storage) currently have our VVol implementation in beta. So I can finally start digging into some VVol work. Not going to get into implementation details just yet, but instead a quick walkthrough of importing a VVol snapshot with PowerCLI.
First, enjoy a poorly photoshopped Back To the Future reference:
The FlashArray Storage Replication Adapter for VMware Site Recovery Manager supports many:many replication since the 2.0 release of the SRA. Use of test failover, failover and reprotect is no different than with 1:1, and nor is the setup of the volumes. The only real difference is how you configure the array managers in SRM. So let’s review how this is done.
So a few updates. I just updated my vSphere Best Practices guide and it can be found here:
I normally do not create a blog post about updating the guide, but this one was a major overhaul and I think is worth mentioning. Furthermore, there are a few documents I have written and published that I want to mention.
- FlashArray Plugin for vRealize Orchestrator User Guide
- Implementing FlashArray in a vRealize Private Cloud
This is the second part of this post. In the first post, I explained the fix and how it affected Windows. In this post, we will overview how the change affects Linux-based virtual machines. See the original post here:
I posted about In-Guest UNMAP with Linux VMs in this post:
One thing you can note is that automatic UNMAP works quite well, but manual UNMAP, like fstrim did not. So let’s revisit fstrim now that this patch is out. Continue reading In-Guest UNMAP Fix in ESXi 6.5 Part II: Linux
As you might’ve seen, Cormac Hogan just posted about an UNMAP fix that was just released. This is a fix I have been eagerly awaiting for some time, so I am very happy to see it released. And thankfully it does not disappoint.
First off, some official information:
Manual patch download:
Or you can run esxcli if you ESXi host has internet access to download and install automatically:
esxcli software profile update -p ESXi-6.5.0-20170304001-standard -d https://hostupdate.vmware.com/software/VUM/PRODUCTION/main/vmw-depot-index.xml
So I am in the middle of updating my best practices guide for vSphere on FlashArray and one of the topics I am looking into providing better guidance around is ESXi queue management. This breaks down to a few things:
- Array volume queue depth limit
- Datastore queue depth limit
- Virtual Machine vSCSI Adapter queue depth limit
- Virtual Disk queue depth limit
I have had more than a few questions lately about handling this–either just general queries or performance escalations. And generally from what I have found it comes down to fundamental understanding of how ESXi queuing works. And how the FlashArray plays with it. So I put a blog post together of a use case and walking through solving a performance problem. Explaining concepts along the way.
- This is a simple example to explain how queuing works in ESXi
- Mileage will vary depending on your workload and configuration
- This workload is targeted specifically to make relationships easier to understand
- PLEASE do not make changes in your environment at least until you read my conclusion at the end. And frankly not without direct guidance from VMware support.
I am sorry, this is a long one. But hopefully informative!
Continue reading Understanding VMware ESXi Queuing and the FlashArray