M1nd3
Contributor
Contributor

vSAN configuration

Hello, I am trying to configure vSAN. Purchased some Dell SAS type disks for flash and storage. There is no problem to assign SAS type disks either to be flash or HDD for storage. But when tried to configure witness node, it doesn't see any available disks for flash. I got rid off all partitions, tried to set disk as RAID but it still cant be seen. There must be something i am missing or don't know.

In worst case i could use a Single site cluster configuration for vSAN. I tried to look for some info about how it works, but wasn't very successful. Could anyone briefly describe the difference between 2 node and witness and single site cluster, and if there are any reasons why single site cluster shouldn't be used?

Thank you for your time and help.

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5 Replies
TheBobkin
VMware Employee
VMware Employee

@M1nd3 You can mark the devices as Flash either via CLI, vSphere client or in the Witness Appliance VM configuration:

https://docs.vmware.com/en/VMware-vSphere/7.0/com.vmware.vsphere.vsan-planning.doc/GUID-42E65085-1DA...

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M1nd3
Contributor
Contributor

Hi @TheBobkin  this link doesn't work, displays 404 error.

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TheBobkin
VMware Employee
VMware Employee

Weird, there was something wrong with the link but I literally just copied it identically and it works now.

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M1nd3
Contributor
Contributor

@TheBobkin  Yes it works now, though it shows how to make storage devices from flash not flash from storage.

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TheBobkin
VMware Employee
VMware Employee

@M1nd3 "changing capacity storage to the flash, is it possible to do so? Or for witness flash disk only SDD can be used? Thank you for your assistance."

Sorry, I think started with some incorrect presumptions here - are you using a Witness appliance (e.g. a VM) or a physical server as Witness role? There isn't really much benefit to using a physical node and the vast vast majority of vSAN customers use Witness appliances - these are deployed with 2-4 vmdks (based on Witness size) with 1 being a Cache-tier device (e.g. seen as an SSD) and 1-3 Capacity-tier devices which by default are seen as HDDs (but which can be changed as mentioned above). If you are using a physical node as Witness there is no way to make it see a HDD as an Cache-tier SSD.

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