Virtual SAN

Opvizor Performance Analyzer for vSAN

10 July, 2018 Leave a Comment

At a VMUG a couple of months ago I bumped into my old friend Dennis Zimmer. Dennis told me that he was working on something cool for vSAN but couldn’t reveal what it was just yet. Last week I had a call with Dennis about what that thing was. Dennis is the CEO for Opvizor, and some of you may recall the different tooling that Opvizor has produced over the years, of which the Health Analyzer was probably the most famous one back then. I’ve used it in the past on various occasions and I had various customers using it. During the briefing, Dennis explained to me that Opvizor started focussing on performance monitoring and analytics a while ago as the health analyzer market was overly crowded and had the issue that is was a one-off business (checks once in a while instead of daily use). On top of that, many products now come with some form of health analysis included. (See vSAN for instance.) I have to agree with Dennis, so this pivot towards Performance Monitoring makes much sense to me.

Dennis explained to me how they are seeing more and more customer demand for vSAN performance monitoring especially combined with VMware ESXi, VM and App data. Although vCenter has various metrics, and there’s VROps, he told me that Opvizor has many customers who need more than vCenter or vROPS standard has to offer today and don’t own VROps advanced. This is where Opvizor Performance Analyzer comes in to play and that is why today Opvizor announced they are including vSAN specific dashboards. Now, this isn’t just for vSAN of course. Opvizor Performance Analyzer includes not just vSAN but also vSphere and various other parts of the stack. When talking with Dennis one thing became clear, Opvizor is taking a different approach than most other solutions. Where most focus on simplifying, hiding, and aggregating, the focus for Opvizor is on providing as much relevant detail as possible to fulfill the needs of beginner and professional.

So how does it work? Opvizor provides a virtual appliance. You simply deploy it in your environment and connect it to vCenter and you are ready to go. The appliance collects data every 5 minutes (but 20 seconds intervals of these 5 minutes) and has a retention of up to 5 years. As I said, the focus is on infrastructure statistics and performance analytics and as such Opvizor delivers all the data you ever need.

It doesn’t just provide you with all the info you will ever need. It will also allow you to overlay different metrics, which makes performance troubleshooting a lot easier, and will allow you to correlate and pinpoint particular problems. Opvizor comes with dashboards for various aspects, here are the ones included in the upcoming release for vSAN:

Capacity and Balance
Storage Diskgroup Stats
VM View
Physical disk latency breakdown
Cache Diskgroup stats
vSAN Monitor

Now I said this is the expert´s troubleshooting tool, but Opvizor Performance Analyzer also provided in-depth information about what each metric is / means and provides starter dashboards for beginners. You can simply click on the “i” in the top left corner of the widget and you get all the info about that particular widget.

When you do know what you are looking for you can click, hover, and zoom when needed. Hover over the specific section in the graph and the point in time values of the metrics will pop up. In the case below I was drilling down on a VM in the vSAN cluster and looking at write latency in specific. As you can see we have 3 objects and in particular 2 disks and a “vm name space”.

And this is just a random example, there are many metrics to look at and many different widgets and overviews. Just to give you an idea, here are some of the metrics you can find in the UI:

Latency (for all different components of the stack)
IOPs (for all different components of the stack)
Bandwidth (for all different components of the stack)
Congestion (for all different components of the stack)
Outstanding I/O (for all different components of the stack)
Read Cache Hit rate (for all different components of the stack)\
ESXi vSAN host disk usage
ESXi vSAN host cpu usage
Number of Components
Disk Usage
Cache Usage

And there;s much more, too many to list in this blog. And again, not just vSAN, but there are many dashboards to chose from. If you don’t have a performance monitoring solution yet and you are evaluating solutions like SolarWinds, Turbunomics and others make sure to add Opvizor to that list. One thing I have to say, I spotted a couple of things that I liked to see changed, and I think within 24hrs the Opvizor guys managed to incorporate the feedback. That was a crazy fast turnaround, good to see how receptive they are.

Oh, one more thing I found in the interface, it is these dashboards that deal with things like NUMA. But also things like the Top 10 VMs in terms of IOPS. Both very useful, especially when doing deep performance troubleshooting and optimizing.

I hope that gives you a sense of what they can do. There’s a fully functional 30-day trial, check it out if you want to find out more about Performance Analyzer or simply just want to play around with it. Opvizor announced this brand new version on their own blog here, make sure to give that a read as well!

Adding a fifth (virtual) ESXi host to vCenter Foundation

6 July, 2018 Leave a Comment

When running a 4 node stretched cluster environment it should be possible to use “cheaper” vCenter Server licenses, namely vCenter Foundation. One of the limitations of vCenter Foundation is that you can only manage 4 hosts with it. This is where some customers who wanted to manage a stretched cluster hit some issues. The issue occurs at the point where you want to add the Witness VM to the inventory. Deploying the VM, of course, works fine, but it becomes problematic when you add the virtual ESXi host (Witness Appliance) to the vCenter Foundation instance as vCenter simply will not allow you to add a 5th host. Yes, this 5th host would be a witness, and will not be running any VMs, and even has a special license. Yet, the “add host” wizard does not differentiate between a regular host and a virtual witness appliance.

Fortunately, there’s a workaround. It is fairly straightforward, and it has to do with the order in which you add hosts to vCenter Foundation. If you add the witness VM before the physical hosts then the appliance is not counted against the license. The license count (and allocation) apparently happens after the host has been added, but somehow vCenter does validate beforehand. I guess we do this to avoid abuse.

So if you have vCenter Foundation, and want to build a stretched cluster leveraging a 2+2+1 configuration, meaning 4 physical hosts and 1 witness VM, then simply add the Witness VM to the inventory as a host first and then add the rest. For those wondering, yes this is documented in the release notes of vSphere 6.5 Update, all the way at the bottom.

How to simplify vSAN Support!

25 May, 2018 5 Comments

Last week I presented at the Tech Support Summit in Cork with Cormac. Our session was about the evolution of vSAN, where are we today but more importantly which directly will we be going. One thing that struck me when I discussed vSAN Support Insight, the solution we announced not to long ago, is that not too many people seemed to understand the benefit. When you have vSAN and you enable CEIP (Customer Experience Improvement Program) then you have a phone home solution for your vSphere and vSAN environment automatically. What this brings is fairly simple to explain: less frustration! Why? Well the support team will have, when you provide them your vCenter UUID, instant access to all of the metadata of your environment. What does that mean? Well the configuration for instance, the performance data, logs, health check details etc. This will allow them to instantly get a good understanding of what your environment looks like, without the need for you as a customer to upload your logs etc.

At the event I demoed the Support Insight interface, which is what the Support Team has available, and a lot of customers afterwards said: now I see the benefit of enabling this, I will do this for sure when I get back to the office. So I figured I would take the demo, do a voice over and release it to the public. We need more people to join the customer experience improvement program, so watch the video to see what this gives the support team. Note by the way that everything is anonymized, without you providing a UUID it is not possible to correlate the data to a customer. Even when you provide a UUID the support team can only see the host, vm, policy and portgroup (etc) names when you provide them with what is called an obfuscation map (key). Anyway, watch the demo and join now!

What’s new vSAN 6.7

17 April, 2018 4 Comments

As most of you have seen, vSAN 6.7 just released together with vSphere 6.7. As such I figured it was time to write a “what’s new” article. There are a whole bunch of cool enhancements and new features, so let’s create a list of the new features first, and then look at them individually in more detail.

HTML-5 User Interface support
Native vRealize Operations dashboards in the HTML-5 client
Support for Microsoft WSFC using vSAN iSCSI
Fast Network Failovers
Optimization: Adaptive Resync
Optimization: Witness Traffic Separation for Stretched Clusters
Optimization: Preferred Site Override for Stretched Clusters
Optimization: Efficient Resync for Stretched Clusters
New Health Checks
Optimization: Enhanced Diagnostic Partition
Optimization: Efficient Decomissioning
Optimization: Efficient and consistent storage policies
4K Native Device Support
FIPS 140-2 Level 1 validation

Yes, that is a relatively long list indeed. Lets take a look at each of the features. First of all, HTML-5 support. I think this is something that everyone has been waiting for. The Web Client was not the most loved user interface that VMware produced, and hopefully the HTML-5 interface will be viewed as a huge step forward. I have played with it extensively over the past 6 months and I must say that it is very snappy. I like how we not just ported over all functionality, but also looked if workflows could be improved and if presented information/data made sense in each and every screen. This also however does mean that new functionality from now on will only be available in the HTML-5 client, so use this going forward. Unless of course the functionality you are trying to access isn’t available yet, but most of it should be! For those who haven’t seen it yet, here’s a couple of screenshots… ain’t it pretty? 😉

For those who didn’t notice, but in the above screenshot you actually can see the swap file, and the policy associated with the swap file, which is a nice improvement!

The next feature is native vROps dashboards for vSAN in the H5 client. I found this very useful in particular. I don’t like context switching and this feature allows me to see all of the data I need to do my job in a single user interface. No need to switch to the VROps UI, but instead vSphere and vSAN dashboards are now made available in the H5 client. Note that it needs the VROps Client Plugin for the vCenter H5 UI to be installed, but that is fairly straight forward.

Next up is support for Microsoft Windows Server Failover Clustering for the vSAN iSCSI service. This is very useful for those running a Microsoft cluster. Create and iSCSI Target and expose it to the WSFC virtual machines. (Normally people used RDMs for this.) Of course this is also supported with physical machines. Such a small enhancement, but for customers using Microsoft clustering a big thing, as it now allows you to run those clusters on vSAN without any issues.

Next are a whole bunch of enhancements that have been added based on customer feedback of the past 6-12 months. Fast Network Failovers was one of those. Majority of our customers have a single vmkernel interface with multiple NICs associated with them, some of our customers have a setup where they create two vmkernel interfaces on different subnets, each with a single NIC. What that last group of customers noticed is that in the previous release we waited 90 seconds before failing over to the other vmkernel interface (tcp time out) when a network/interface had failed. In the 6.7 release we actually introduce a mechanism that allows us to failover fast, literally within seconds. So a big improvement for customers who have this kind of network configuration (which is very similar to the traditional A/B Storage Fabric design).

Adaptive Resync is an optimization to the current resync function that is part of vSAN. If a failure has occurred (host, disk, flash failure) then data will need to be resynced to ensure that the impacted objects (VMs, disks etc) are brought in to compliance again with the configured policy. Over the past 12 months the engineering team has worked hard to optimize the resync mechanism as much as possible. In vSAN 6.6.1 a big jump was already made by taking VM latency in to account when it came to resync bandwidth allocation, and this has been further enhanced in 6.7. In 6.7 vSAN can calculate the total available bandwidth, and ensures Quality Of Service for the guest VMs prevails by allocating those VMs 80% of the available bandwidth and limiting the resync traffic to 20%. Of course, this only applies when congestion is detected. Expect more enhancements in this space in the future.

A couple of release ago we introduced Witness Traffic Separation for 2 Node configurations, and in 6.7 we introduce the support for this feature for Stretched Clusters as well. This is something many Stretched vSAN customers have asked for. It can be configured through the CLI only at this point (esxcli) but that shouldn’t be a huge problem. As mentioned previously, what you end up doing is tagging a vmknic for “witness traffic” only. Pretty straight forward, but very useful:

esxcli vsan network ip set -i vmk<X> -T=witness

Another enhancement for stretched clusters is Preferred Site Override. It is a small enhancements, but in the past when the preferred site failed and returned for duty but would only be connected to the witness, it could happen that the witness would bind itself directly to the preferred site. This by itself would result in VMs becoming unavailable. This Preferred Site Override functionality would prevent this from happening. It will ensure that VMs (and all data) remains available in the secondary site. I guess one could also argue that this is not an enhancement, but much more a bug fix. And then there is the Efficient Resync for Stretched Clusters feature. This is getting a bit too much in to the weeds, but essentially it is a smarter way of bringing components up to the same level within a site after the network between locations has failed. As you can imagine 1 location is allowed to progress, which means that the other location needs to catch up when the network returns. With this enhancement we limit the bandwidth / resync traffic.

And as with every new release, the 6.7 release of course also has a whole new set of Health Checks. I think the Health Check has quickly become the favorite feature of all vSAN Admins, and for a good reason. It makes life much easier if you ask me. In the 6.7 release for instance we will validate consistency in terms of host settings and if an inconsistency is found report this. We also, when downloading the HCL details, will only download the differences between the current and previous version. (Where in the past we would simply pull the full json file.) There are many other small improvements around performance etc. Just give it a spin and you will see.

Something that my team has been pushing hard for (thanks Paudie) is the Enhanced Diagnostic Partition. As most of you know when you install / run ESXi there’s a diagnostic partition. This diagnostic partition unfortunately was a fixed size, with the current release when upgrading (or installing green field) ESXi will automatically resize the diagnostic partition. This is especially useful for large memory host configurations, actually useful for vSAN in general. No longer do you need to run a script to resize the partition, it will happen automatically for you!

Another optimization that was released in vSAN 6.7 is called “Efficient Decomissioning“. And this is all about being smarter in terms of consolidating replicas across hosts/fault domains to free up a host/fault domain to allow for maintenance mode to occur. This means that if a component is striped, for other reasons then policy, they may be consolidated. And the last optimization is what they refer to as Efficient and consistent storage policies. I am not sure I understand the name, as this is all about the swap object. Per vSAN 6.7 it will be thin provisioned by default (instead of 100% reserved), and also the swap object will now inherit the policy assigned to the VM. So if you have FTT=2 assigned to the VM, then you will have not two but three components for the swap object, still thin provisioned so it shouldn’t really change the consumed space in most cases.

Then there are the two last items on the list: 4K Native Device Support and FIPS 140-2 Level 1 validation. I think those speak for itself. 4K Native Device Support has been asked for by many customers, but we had to wait for vSphere to support it. vSphere supports it as of 6.7, so that means vSAN will also support it Day 0. The VMware VMkernel Cryptographic Module v1.0 has achieved FIPS 140-2, vSAN leverages the same module for vSAN Encryption. Nice collaboration by the teams, which is now showing the big benefit.

Anyway, there’s more work to do today, back to my desk and release the next article. Oh, and if you haven’t seen it yet, Virtual Blocks also has a blog and there’s a nice podcast on the topic of 6.7 as well.

22 / 23 May 2018 – VMware Technical Support Summit

17 April, 2018 Leave a Comment

A while back I was asked if I could present at the VMware Technical Support Summit and last week I received the agenda. I forgot to blog about it so I figured I would share it with everyone. I was supposed to go to this event last year but I had a clash in my calendar unfortunately. At this event organized by our support team you will have the ability to sit in some extreme deep dive sessions. Below you can find the agenda, and also here’s the registration link if you are interested! Note that Joe Baguley will be doing a keynote, and Cormac Hogan and I will be doing a session on vSAN futures!