Question

Override Installer CVM boot disk size requirement

  • 6 January 2021
  • 3 replies
  • 155 views

Hi,

First time attempting to install Nutanix. I’m experienced with VMWare, but I wanted to try out Nutanix, mainly as I read it will allow me to create a single-node cluster, using locally attached NVMe disks without the overhead (headache) of vSAN (that doesn’t work as a single-node).

Running through the installer, I see I have to specify an AHV (equivalent of ESX?) boot disk and CVM boot disk that requires a disk of at least 200GB. 

If I understand correctly, CVM is the equivalent of vCentre Server (VCSA).

Firstly, can I install this CVM somewhere else?

Secondly, I don’t have a separate disk of >=200GB that I want to waste on CVM. I have a 128GB SSD that I would have used for data, but the installer won’t let me and I can’t use it for CVM either because it’s too small. If I can’t farm off the CVM to another device, is there a way to override this limitation? Even fat old VCSA only uses 72GB across its 13 disks. What is in CVM!

 

These are my disks. As you can see, to install CVM on its own disk is going to waste valuable storage.

Device Size (GB) Intended use
NVMe 500 Data
NVMe 500 Data
SSD 128 Data (or CVM if I must)
SSD 1000 Data
DOM 64 AHV (ideally + CVM)
HDD 8000 Data

 

Thank you in advance.


3 replies

Userlevel 5
Badge +16

I suggest you to read a bit about Nutanix first before you start excluding disks from CVM: https://next.nutanix.com/how-it-works-22/disk-structure-of-a-cvm-37930

Userlevel 6
Badge +5

Hi woter324,

First of all, CVM does not perform functions similar to the Center. If I was to draw parallels, Prism Central would be a similar thing to the VC. VC is the management layer. Your cluster can live without VC. You can’t live without a CVM. In a multi-node cluster, you can’t live without a CVM on each node. CVM serves storage apart from a miriad of other things.

Take a look at Nutanix Bible: Hyperconverged Platform, Nutanix Bible: Book of AHV: Node architecture

AHV is a hypervisor, so is ESXi. AHV is a Nutanix hypervisor while ESXi is developed by VMware.

Badge +1

Ok… next issue… my SSD is reported as 199.447 GB instead of 200 GB, so I cannot install CVM on it. How can I force it to ignore the rounding error?

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