Simplivity Zones

[Yasha1004]

Hello, good morning

I am a bit confused about the simplivity zones.

Is it necessary that the cluster is Stretched or is it possible to configure zones without the Stretched configuration?

Currently I have a client with 4 nodes and has zones configuration, but I can not find a way to know if that cluster is Stretched.

Greetings,

[Sanika]

Hi Yasha1004,

Stretched clusters provide even more protection, where service continues even with multiple HPE OmniStack host failures across a rack, lab, or even an entire site. In contrast, a non-stretched or local cluster has all nodes within the same location i.e in same physical locations or data centers.

Clusters with zones in SimpliVity do not have to be "Stretched." You can configure zones even if they are not stretched.

Here's how you can determine if your client's cluster with 4 nodes and zone configuration is stretched:

1. Stretched Clusters are supported with an even number of HPE OmniStack hosts. Hosts must be equally distributed in the two Availability Zones within the cluster.  Stretched Clusters are not supported with an odd number of hosts.
2. Stretched Cluster configurations support up to 16 HPE OmniStack hosts.
3. Stretched cluster require low-latency connections between availability zones. The recommended max latency value is 2ms and a 10Gbps connection.

You may refer the below documentation and video links which explains in detail about Stretched Clusters and Availability Zones:

https://support.hpe.com/hpesc/public/docDisplay?docLocale=en_US&docId=a00131388en_us (From page no.53)

HPE SimpliVity - Stretch Clusters - Overview
https://support.hpe.com/hpesc/public/videoDisplay?videoId=vtc00000092en_us

HPE SimpliVity - Stretch Clusters - Configure
https://support.hpe.com/hpesc/public/videoDisplay?videoId=vtc00000095en_us

HPE SimpliVity - Stretch Clusters - Unconfigure
https://support.hpe.com/hpesc/public/videoDisplay?videoId=vtc00000091en_us

Hope you find it useful.

Regards,
Sanika.

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[Sanika]

Hello @Yasha1004 

Let me know if you were able to resolve the issue.

If you have no further query and you are satisfied with the answer then kindly mark the topic as Solved so that it is helpful for all community members.

Regards,
Sanika.

[Stefano_Colombo]

Hello,

following this thread I've a question about migrating from non-zoned cluster to a zoned configuration

with a cluster of 3 nodes on the same rack we'd like to move to a zoned configuration by adding a fourth node and a different rack in a different campus location.

So what would be the correct path to get to a zoned configuration?

thanks

[Sanika]

Hi @Stefano_Colombo 

In order to get to a zoned configuration, you may define Availability Zones where Zone 1 has 3 nodes and Zone 2 has new node.
Ensure low latency & high-bandwidth connection between zones.

Below are some steps that may help you:

1. Deploy the new node in the seperate rack using SimpliVity Deployment Manager & ensure the new node has the same software version as the existing cluster.
2. To create availability zone, run the command svt-zone-create --name <name of the zone>
(eg: svt-zone-create --name Zone1 , svt-zone-create --name Zone2)
3. To assign nodes to their respective zones, run the command svt-zone-assign --zone <name of the zone> --host <name of the host> i.e assign existing nodes to Zone1 and new node to Zone2
4. After configuration, finalize the planned zone configuration changes and make them effective by running the command svt-zone-realize --cluster <name of the cluster>. This automatically migrates VMs to comply with zone policies (might cause slight I/O performance impact)
5. Lastly, verify zone configuration using svt-cli commands or by logging in to vSphere client (GUI).

Hope this helps.

Regards,
Sanika.

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[Stefano_Colombo]

Hello @Sanika 

thanks for your support, I've got a question about this step

3. To assign nodes to their respective zones, run the command svt-zone-assign --zone <name of the zone> --host <name of the host> i.e assign existing nodes to Zone1 and new node to Zone2

We'd like to get to a situation with 2 nodes on each zone, so we'll assign two nodes each.

when we'll apply it I suppose that each VM might get one of its copy moved to the host in the separate zone.

Hopefully there will be a maximum of VM that gets moved at the same time, right ?

[Sanika]

Hi @Stefano_Colombo 

Yes, the svt-zone-assign command allows you to assign 2 nodes to each zone and a stretched cluster will have a copy of the VM on each availability zone.

But, in my opinion, it may not gurantee that every VM will have a copy automatically moved to the seperate zone. Zone realisation and defined policies are the key factors that determine VM movement and how VMs are distributed across zones.

In order to get further clarification and more accurate information on this, I would request you to contact HPE support.

Hope this helps.

Regards,
Sanika.

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[JustinPham]

Hi,

I have a scenario:

Total hosts: 6 (even number)

DC Site 1 (AZ1): 3 hosts

DC Site 2 (AZ2): 3 hosts

Distribution: Equal across both availability zone

This case makes sense, right?

Hope to hear your response on this case!