thecoffeeshop
Contributor
Contributor

vSAN implementation question

Hello folks.

As I am testing and becoming more familiar with vSAN (i've been testing/playing in a lab environment) I have a question regarding implementing vSAN on an existing infrastructure.

For testing purposes, I have a two node cluster with local storage.

I have vCenter running virtualized on one of my ESXi nodes. vSAN is currently not running or configured (on purpose for testing).

Now, as I prep to enable vSAN on these two nodes, my only real question is do I lose my data/vm's on those local drives? (I have two dedicated drives that will act as the caching drives for each esxi node.)

i ask because, vcenter is virtual and has a lot of configs (networking, admin etc.) so my concern is do I lose that VM and all the configurations on it? (I could probably back it up, need to research).


For the VM's that currently exist on the nodes, I am ok with losing them with the vcenter server being the exception (its the virtual appliance btw).

Anyway, I hope I explained that well.

Appreciate the help.

TCS

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3 Replies
TheBobkin
VMware Employee
VMware Employee

Hello thecoffeeshop​,

Please validate that the local disks are on the vSAN HCL for the intended purpose (e.g. All-Flash/Hybrid Caching/Capacity tier), that is unless this is purely for testing purposes and you are aware of the risks of using unsupported hardware. And also of course, the controller these are attached to.

VMware Compatibility Guide - vsan

https://hcl.captain-vsan.com/

"Now, as I prep to enable vSAN on these two nodes, my only real question is do I lose my data/vm's on those local drives? (I have two dedicated drives that will act as the caching drives for each esxi node.)"

A couple of relevant points:

1. You require one Cache-tier SSD/NVMe and at least one Capacity-tier SSD/NVMe/HDD per Disk-Group.

2. You will require a 3rd node or somewhere else to run a Witness Appliance if going with that option.

3. vSAN cannot claim devices for use unless they have no partitions on them, so if you want to use the local disks for vSAN then whatever on them needs to be moved off and the partitions removed.

4. vSAN requires adequate licensing to enable it in addition to ESXi/vSphere licensing - you can of course enable it with an Evaluation license but this not a long-term solution.

Bob

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thecoffeeshop
Contributor
Contributor

Hello Thebobkin,


yes, i verified the drives are all on the HCL and they are.

Walking down the list and adding/responding:

1.) Yes, that was the plan. one SSD per host is what I was planning (only two esxi hosts)

2.) for the 3rd node, is that an actual esxi host? If so, is it not possible to run vSAN with 2 nodes?

3.) Makes sense and I had a feeling that may be the case.

4.) yes, we are good to go on licensing. I made sure of that.

I appreciate the feedback and help.

Greatly appreciated.

Cheers,


TCS

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TheBobkin
VMware Employee
VMware Employee

Hello thecoffeeshop​,

"2.) for the 3rd node, is that an actual esxi host? If so, is it not possible to run vSAN with 2 nodes?"

vSAN requires a minimum of 3 nodes if you want to configure it with proper redundancy, while it is technically feasible to run it on even 1 node, data will be FTT=0 in anything less than a 3-node cluster.

You can use a 3rd physical host or a Witness VM running somewhere else.

Bob

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