Yellow Bricks

by Duncan Epping

VMware

Intel Optane support for vSAN, first HCI solution to deliver it

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I am in Australia this week for the Sydney and Melbourne VMUG UserCon’s. Had a bunch of meetings yesterday and this morning the news was dropped that Intel Optane support was released for vSAN. The performance claims look great, 2.5x more IOPS and 2.5x less latency. (I don’t know the test specifics yet.) On top of that, Optane typically has a higher endurance rating, meaning that the device can incur a lot more writes, which makes it an ideal device for the vSAN caching layer.

While talking to customers the past couple of days though it was clear to me that performance is one thing, but flexibility of configuration is much more important. With vSAN you have the ability to select any server from the vSphere HCL and pick the components you want as long as they are on the vSAN HCL.  Or you can simply pick a ready node and swap components as needed. As long as the controller remains the same for a ready node you can do that. Either way, you have choice, and now with Optane being certified you can use the latest in flash technology with vSAN!

Oh for those paying attention, the Intel P4800X Optane device isn’t listed on the HCL yet. The database is being updated as we speak, and the device should be included soon!

Running a Witness Appliance on a 2 Node vSAN config with FT

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I have had various people asking, and to me it felt like an obvious answer, but as multiple have asked over the past couple of month I figured I would dedicate a post to it. The question is if it is supported to run the vSAN Witness Appliance for a 2 Node vSAN configuration on the 2 Node vSAN Configuration itself, but then with vSphere SMP-FT enabled on the Witness for extra protection.

The short answer: No, this is not supported.

The slightly longer answer: No, this is not supported. The vSAN Witness needs to run outside of the vSAN cluster it is acting as a witness for. The reason for this is fairly straight forward: Just imagine the vSAN hosts are partitioned and cannot talk to each other, yet both may have access to the Witness as a result of FT doing what it is designed to do. But those are different instances of the same Witness, which potentially can lead to all sorts of strange problems.

Startup intro: Runecast

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I met with Runecast a couple of years ago at VMworld. Actually, I am not sure they already had a name back then, I should probably say I met with the guys who ended up founding Runecast at VMworld. One of them, Stan, is a VCDX and back then he pitched this idea to me around an appliance that would analyze your environment based on a set of KBs. His idea was primarily based on his experience managing and building datacenters. (Not just Stan’s experience, but most of the team are actually former IBM employees) Interesting concept, kind of sounded similar to CloudPhysics to me, although the focus was more on correlation of KB then capacity management etc.

Fast forward to 2017 and I just finished a call with the Runecast team. I had a short conversation at VMworld 2016 and was under the impression that they sold the company or quit. None of this is true. Runecast managed to get a 1.6m euro funding (Czech Republic) and is going full steam ahead. With around 10 people, most being in Czech Republic they are ready to release the next version of Runecast Analyzer, which will be 1.5. So what does this provide?

Well just imagine you manage a bunch of hosts and vCenter (not unlikely when you visit my blog), maybe some shared storage along with it. There are many KB articles, frequent updates of these and many newly published KBs every week. Then there’s also a whole bunch of best practices and of course the vSphere Hardening Guide. As an administrator do you have time to read everything that is published every day? And then when you have read it, do you have time to check your environment if the issue or best practice described applies to your infrastructure? Of course you don’t, and this is where Runecast Analyzer comes in to play.

You download the appliance and provision it in to your environment, next you simply hook vCenter Server in to it and off you go. (As of 1.5 it also supports connecting several vCenter Server instances by the way.) Click analyze now and check the issues called out in the HTML-5 dashboard. As the screenshot below shows, this particular environment has issues identified in the log file that are described in a KB article. There are various other KB articles that may apply, just as an example: a combination of a certain virtual NIC with a specific OS may not be recommended. Also, various potential security issues and best practices are raised if they exist/apply.

When you would click one of these areas you can drill down in to what the issue is and potentially figure out how to mitigate it. In the screenshot below you see the list of KBs that apply to this particular environment, you can open the particular entry (second screenshot below) and then find out to what it applies (objects: VMs, hosts, vCenter etc). If you feel it doesn’t apply to you, or you accept the risk, you can of course “ignore” the issue. When you click ignore a filter will be created which rules out this issue from being called out through the dashboard. The filtering mechanism is pretty smart, and you can easily create your own filters on any level of the virtual infra hierarchy. Yes, it is also possible to delete the filter(s) again when you feel it does apply to your environment.

Besides checking the environment, as mentioned, Runecast can also analyze the logs for you. And I was happy to see that this got added, as it makes it unique compared to other solutions out there. Depending on what you are looking for you have these quick filtering options, and of course there are search strings and you can select a time period in which you would like to search of this particular string

As I said, all of this comes as a virtual appliance, which does not require direct connection to the internet. However, in order to keep the solution relevant you will need to update regularly, they mentioned they release a new data set once every two weeks roughly. It can be updated over the internet (through a proxy if needed), or you can download the ISO and update Runecast Analyzer through that, which could be very useful in secure locations. The appliance works against vSphere 5.x and 6.x (yes including 6.5) and there is a 30 day free trial. (Annual subscription, per socket pricing.) If you like to give it a try, click the banner on the right side, or go to their website: https://www.runecast.biz/. Pretty neat solution, and looking forward seeing what these guys can achieve with the funding they just received.

Virtually Speaking Podcast – vSAN Customer Use Cases

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As John Nicholson was traveling in and around New Zealand I was asked by Pete if I could co-host the Virtually Speaking Podcast again. It is always entertaining to join, Pete is such a natural when it comes to these things. I euuh, well I do my best to keep up with him :). Below you can find the latest episode on the topic of vSAN Customer Use Cases. It includes a lot of soundbites recorded at VMware World Wide Kick Off / Tech Summit, which is a VMware internal event for all Sales, Pre-Sales and Post-Sales field facing people.

You can of course also subscribe on iTunes!

VVols design and procurement considerations

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Over the past couple of months I have had more and more discussions with customers and partners about VVols. It seems that Policy Based Management and the VVol granular capabilities are really starting to sink in, and more and more customers are starting to see the benefit of using vSphere as the management plane. The other option of course is pre-defining what is enabled on a datastore/LUN level and use spreadsheets and complex naming schemes to determine where a VM should land, far from optimal. I am not going to discuss the VVols basics at this point, if you need to know more about that simply do a search on VVol.

When having these discussions a bunch of things typically come up, these all have to do with design and procurement considerations when it comes to VVol capable storage. VMware provided a framework, and API, and based on this each vendor has developed their own implementation. These vary from vendor to vendor, as not all storage systems are created equal. So what do you have to think about when designing a VVols environment or when you are procuring new VVol capable storage? Below you find a list of questions to ask, with a short explanation of why this may be important. I will try to add new questions and considerations when I come up with them.

  • What level of software is needed for my storage system to support VVol?

In many cases, especially existing legacy storage systems, an upgrade is needed of the software to support VVols, ask:

  • What does this upgrade entail?
  • What is the risk?

When it is clear what you need to support VVols from a software point of view, ask:

  • What are the constraints and limits?
    • How many Protocol Endpoints can I have per storage system?
      • Do you support all protocols? (FC, NFS, iSCSI etc)
      • Is the IO proxied via the Protocol Endpoint? If it is, is their an impact with a large number of VMs?
        • Some systems can make a distinction between traffic type and for normal IO will not go through the PE, which means you don’t hit any PE limitations (queue depth being one)
    • How many Storage Pools can you have per storage system?
      • In some cases (legacy storage systems) the storage pool equals an existing physical construct on the array, what is it and what is the impact of this?
        • What kind of options do I select during the creation of the pool? Anything you select on a per Pool level means that when you change policy VVols may have to migrate to other pools, I prefer to avoid data movement. In some cases for instance “replication” is enabled on a storage pool level, I prefer to have this as a policy option
    • How many VVols can I have per storage system? (How many VMs do you have, and how many VVols do you expect to have per VM?)
      • In some cases, usually legacy storage systems, the number of VVols per array is limited. I have seen as “low” as 2000, with 3 VVols per VM at a mininum (typical 5) you can imagine this restricts the number of VMs you can run on single storage system

And then there is the control / management plane:

  • How is the VASA (vSphere APIs for Storage Awareness) Provider implemented?
    • There are two options here, either it comes as part of the storage system or it is provided as a virtual machine.
  • Then as part of that there’s also the decision around the availability model of the VASA Provider:
    • Is it a single instance?
    • Active/Standby?
    • Active/Active?
    • Scale-out?

Note, as it stands today, in order to power-on a VM or create a VM the VASA Provider needs to be available. Hence the availability model is probably of importance, depending on the type of environment you are designing. Also, some prefer to avoid having it implemented on the storage system, as any update means touching the storage system. Others prefer to have it as part of the storage system as it removes the need to have a separate VM that needs to be managed and maintained.

Last but not least, policy capabilities:

  • What is exposed through policy?
    • Availability? (RAID type / number of copies of object)
    •  QoS?
      • Reservations
      • Limits
    • Replication?
    • Snapshot (scheduling)?
    • Encryption?
    • Application type?
    • Thin provisioning?

I hope this helps having the conversation with your storage vendor, developing your design or guide the conversation during the procurement process. If anyone has additional considerations please leave a comment so I can add it to the list when applicable.