{"id":28600,"date":"2023-05-31T17:11:32","date_gmt":"2023-05-31T15:11:32","guid":{"rendered":"https:\/\/blog.miniserver.it\/?p=28600"},"modified":"2023-05-31T17:11:32","modified_gmt":"2023-05-31T15:11:32","slug":"how-to-size-a-2-node-proxmox-ve-cluster","status":"publish","type":"post","link":"https:\/\/blog.miniserver.it\/en\/proxmox-ve\/how-to-size-a-2-node-proxmox-ve-cluster\/","title":{"rendered":"How to Size a 2 Node Proxmox VE Cluster"},"content":{"rendered":"

In this article we wil cover the sizing ofa 2 node Proxmox VE cluster.<\/span><\/p>\n<\/div><\/div><\/div>

The Steps for Sizing the 2 Node Proxmox VE Cluster<\/span><\/h2><\/div>
<\/div><\/div><\/div><\/div>

1. Operating principles of a 2 node cluster<\/h3>\n

The 2 node cluster actually consists of three parts. It’s called a 2 node cluster because it has two processing nodes (pve1 \/ node 1, pve2 \/ node 2) that run the containers and virtual machines.<\/p>\n

The third node maintains quorum. The minimum number of nodes for a true cluster system is 3.<\/p>\n

The third node is not a processing node but a Proxmox Backup Server and is used for backups.<\/p>\n

Unlike the 3 node cluster, the 2 node cluster is not hyper-converged, so it doesn’t use the Ceph framework.<\/b><\/a><\/p>\n

Redundancy of the resources between the 2 nodes is managed by a replication system: all resources running on Node 1 are replicated on Node 2 and vice versa.<\/p>\n<\/div><\/div><\/div>

2. The resources needed for correct sizing<\/h3>\n

\"How<\/p>\n

Let’s take a concrete example of configuration. Similar to the<\/span> sizing of a 3 node Proxmox VE hyper-converged cluster<\/b><\/a>, let’s look at the characteristics required by the VMs and CTs that populate the cluster. <\/span><\/span><\/p>\n

This will help to understand how many resourses and what resources the cluster will need and in particular the individual nodes.<\/span><\/span><\/p>\n

In the following example, we have simulated the classic needs of a small\/medium company: <\/span><\/p>\n

HR Software, a domain controller with file server, a ticket management system, a RDP VM (Virtual Machine) on Windows and a 3CX Phone System.<\/span><\/p>\n

For each of these machines we have reported the required space, the number of cores and number of RAM GB.<\/span><\/p>\n

We get the totals column trivially with sums, and then add between 10% and 15% dedicated to the hypervisor.<\/p>\n

If you design a cluster today, consider it will remain in production for a few years (from 3 to 7-8 years), depending on company policies.<\/p>\n

It is likely that the cluster load will increase: because operating systems demand more resources or because company management asks you to install new machines.<\/p>\n

It would be wrong to size a cluster thinking only of today’s needs. You have to calculate some leeway for the future.<\/p>\n

In this example, we calculate a 50% future growth.<\/p>\n

With the total resources for the two nodes and make the following argument: for the 2 node cluster to always be functional, it must enable operation with all the load (VM and CT) on a single node which needs to handle all the load.<\/p>\n

If this condition is not met, the concept of redundancy and Fault Torerance, which is the basis of the cluster, is lost.<\/p>\n

For instance, if you do maintenaning one node 1, you can move the resources from Node 1 to Node 2 while running. That is, while users are working.<\/p>\n

Ad esempio, nel caso di manutenzione node 1: baster\u00e0 spostare le risorse dal Nodo 1 al Nodo 2 a caldo (ovvero mentre gli utenti lavorano).<\/p>\n

At the end of maintenance work, you transfer the resources back to node 1 thus balancing the load on the 2 nodes again.<\/p>\n

In our example, the single cluster node resources will be about 3.5 TB of data storage, 28 Cores and 200 GB of RAM.<\/p>\n

Once hardware characteristics of the single node have been defined, proceed to request a quote to get a financial quantification of the investment.<\/p>\n

Let’s now choose one of the 2 node Proxmox VE clusters to size it. We’ll choose the of the <\/span>M1N2<\/b><\/a> Cluster.<\/span><\/span><\/p>\n

If unsure, leave the default values selected. We will take a look at the quote before sending it to you.<\/p>\n

3. The number of cores <\/span><\/h3>\n

\"\"<\/p>\n

This cluster is made with two nodes and Proxmox Backup Server as mentioned above before.<\/span><\/p>\n

Select the number of cores (from the exampe it came to 28). You can round up or down, depending on what you need. In this example we selected 32 cores.<\/p>\n

We could have also selected 24 cores, bearing in mind that however we could encounter a shortage of resources over time.<\/span><\/p>\n

4. RAM del cluster<\/h3>\n

\"RAM<\/p>\n

We round up 200GB of RAM to 256GB of RAM.<\/p>\n

5. Operating system<\/h3>\n

\"Operating<\/p>\n

Select for example a Proxmox VE Community Edition<\/b><\/a> subscription.<\/p>\n

6. Operating system storage<\/h3>\n

\"Storage
\n
\nFor the operating system 128GB of space is more than enough.<\/span><\/p>\n

7. Cluster storage<\/h3>\n

\"Cluster<\/p>\n

4 TB would be closer to 3840 GB.
\n<\/span><\/p>\n

8.Additional network cards<\/span><\/h3>\n

\"Cluster<\/p>\n

By default we selected 2 25 Gb NICs and 4 10Gb NICs in fiber, because at least 6 NICs are required for clusters of this range. Clearly each configuration must be redundant, so that a port failure cannot affect system functioning.<\/p>\n

25 Gbit NICs are typically used for cluster management and backup. 25 Gb speeds are designed to never be saturated by system operations.<\/p>\n

For example, disks used will never be able to reach the speed of 25Gb, therefore won’t saturate the network.<\/p>\n

The other 2 NICs fiber will be used for virtual machines, while the other 2 NICs for replicates.<\/p>\n

On high-end 2 node clusters, 6 NICs are normally used and on entry-level clusters, 4 NICs can also be used, aggregating the functions described above.<\/p>\n

9. Network switch<\/h3>\n

\"Network
\nThe network switch is chosen based on the configuration selected above. To have redundancy on the whole network, we recommend the double switch solution.<\/p>\n

10. PBS storage<\/h3>\n

\"PBS<\/p>\n

Please note that Proxmox Backup Server is a node that is part of the cluster, therefore basically two types of NIC will be used: one will be used for backups and the other for the cluster.<\/p>\n

To get a fully redundant configuration you will need a PBS with at least 4 NICs. Basically we will always install (unless we manage a very small amount of data) a PBS with 4 NICs.<\/p>\n

To calculate the PBS storage space, the reasoning is very simple. Multiply by 2 the storage present on the Proxmox Cluster. For more accurate sizing, versioning and retention of backup versions should be considered.<\/p>\n

If you don’t have special needs, calculating twice the size of the single cluster node is a good compromise.<\/p>\n

The choice between NVMe, SSD and SATA disks is mainly about the performance speed you want to achieve during backup and restore phases.<\/p>\n

NVMe and SSD disks always allow you to maintain excellent speed in both phases.<\/p>\n<\/div><\/div><\/div><\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":11,"featured_media":28666,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"content-type":"","footnotes":""},"categories":[129],"tags":[],"class_list":["post-28600","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-proxmox-ve"],"_links":{"self":[{"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/posts\/28600","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/comments?post=28600"}],"version-history":[{"count":48,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/posts\/28600\/revisions"}],"predecessor-version":[{"id":28668,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/posts\/28600\/revisions\/28668"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/media\/28666"}],"wp:attachment":[{"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/media?parent=28600"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/categories?post=28600"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.miniserver.it\/en\/wp-json\/wp\/v2\/tags?post=28600"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}