Question

Combining a mixed hypervisor cluster with mixed hardware

  • 10 August 2020
  • 3 replies
  • 452 views

We have a 4 node cluster configured as follows:
2 x Lenovo HX1320 (dual 8-core Xeon Silver 4110 CPU @ 2.10 Ghz / 192 GB RAM / 7.11 TB storage) with ESXi
2 x Lenovo HX5520-C (single -core Xeon Silver 4110 CPU @ 2.10 Ghz / 64 GB RAM / 35.83 TB) with AHV

We would like to convert the ESXi nodes to AHV.  Looking at the knowledge base and the community it seems like doing this would allow all 4 nodes to share the virtual machine load and because the CPUs are the same we should not have to worry about compatibility issues.  Is this a correct assumption?  Any issues we should watch for?


3 replies

Userlevel 5
Badge +5

Hi AlanR17,

 

Are those configured as 2-nodes clusters? If so then 2-nodes clusters can’t be expanded. KB-5943

As per the intermixing compatiblity of Lenovo nodes, Nutanix recommendation is to ask Lenovo. I wish I could give you more on this.

Userlevel 3
Badge +4

I assume it’s a single cluster with 4 nodes, 2 of which are AHV storage-only nodes. 

It will work if the cluster is recreated with 4 AHV nodes and all of them can be used for VM workload. However, there are some points:

  1. The HX5520-C nodes have only 64Gb RAM. It won’t be possible to run a lot of VMs on them. The CVM will also consume some of that memory.
  2. Data resiliency will be hard to maintain because the difference in storage size between nodes is huge. For example, if one of the big nodes HX5520-C has a failure, the cluster will be recreating the copies on the remaining nodes and will very quickly run out of space. That applies also to the current config with 2 ESXi and 2 AHV storage-only.

I would consider adding more storage (if possible) to the small nodes HX1320 and adding some memory to HX5520-C. You would need to consult with the hardware vendor (Lenovo) if that is possible.

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As far as I know, Lenovo ThinkSystems servers have all the components of different chassis cross-compatible.
It might make sense to check the compatibility of available disks and memory and swap between servers to balance configurations. But that's in theory and the possibility of this is better aligned with the support.

https://lenovopress.com/lp0991-thinkagile-hx5520-c-appliance-gen1

Table 1. HX5520-C system specifications
Drive bays    12x or 14x 3.5-inch SAS/SATA hot-swap.


https://lenovopress.com/lp0726-thinkagile-hx1320-appliance-gen1

Table 1. HX1320 system specifications

Drive bays    4x 3.5-inch SAS/SATA hot-swap.

Both chassis, HX1320 & HX5520-C have drives of the same form-fact. 

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