When HCI is the WRONG choice

By Ben Marquis – HCI, Cloud, and Storage Solutions Engineer

February 7, 2020

Right now, Hyper-Converged Infrastructure aka HCI is all the rage. Like many new solutions that rapidly gain popularity the hype can often overshadow whether the solution is truly right for your specific requirements. HCI is more than a buzzword, it’s a powerful way to simplify operations, improve user experiences through increased performance, reduce rack-space and save money on support, cooling, and power consumption. That all sounds amazing, right? It is, but HCI simply isn’t right for everyone!

Let’s begin with defining what HCI is. Most modern HCI solutions utilize multiple x86 Server Nodes for compute, storage, and even some network functions. HCI virtualizes all CPU, Memory, Storage & Network resources much the same way a Hypervisor does for a single server. By abstracting resources across multiple server nodes, the HCI software applies data protection for complete resiliency.

When it’s wrong

Some vendors may come in and push their HCI solution even when that solution is not ideal for your requirements. This is not surprising when you consider some of these vendors don’t have anything else in their solutions portfolio to sell you. With Dell EMCs portfolio there are many options available to create the ideal solution for each customer’s unique requirements. Dell EMC not only sells VMware vSAN ready nodes but also turnkey Dell EMC VxRail, Dell Nutanix ready nodes, Dell Azure Stack HCI/MS Storage Spaces Direct (S2D) ready nodes, as well as hardware to accommodate HCI solutions from software vendors including StarWind Software, DataCore, and others. xByte can help you find what’s right for you if you are considering any of these.

There are several instances where HCIs like vSAN, Nutanix, and VxRail struggle to effectively meet performance benchmarks. Here are some circumstances where HCI might be the wrong choice.

  • Large File environments, engineering files, heavy rich media. For these scenarios Dell EMC Isilon is well suited.
  • Large file/object data archival, with minimal hot data. For archive Dell EMC Elastic Cloud Storage (ECS) is going to be one of the most economical choices.
  • Mixed workloads with moderate file environments or block data on Fibre Channel SAN or iSCSI next to File Shares utilizing IP protocols. Dell EMC Unity XT is a versatile and efficient storage platform making it one of the most popular mixed workload storage systems available today.
  • Data that requires heavy deduplication such as specific databases or applications that create lots of snapshots and need powerful copy data management tools for optimum efficiency and performance. XTremIO is designed with these workloads in mind, greater speed, smaller data footprint, & best in class total efficiency.
  • Primary Backup Target – Dell EMC has the most comprehensive Data Protection and Cyber Recovery Solutions in the market. From Power Protect DD, Integrated Data Protection Appliance (IDPA), Power Protect X400, to software such as RecoverPoint, Avamar, and Networker. No matter the challenge, Dell has the ideal solution for your needs!
  • Multi-hypervisor environments, e.g. VMware vSphere for internal VMs & Citrix XenServer for web hosting applications. VxRack Flex would accommodate this type of scenario.

When it’s right

The solution below could be truly outstanding for organizations running traditional apps, cloud-native apps, SaaS Apps, VDI, VMware with VMs containing databases, ERP, AD, DNS, Domain Controllers, print servers, smaller file shares, hybrid-cloud environments etc. vSAN is also great for organizations with moderate to large ROBOs where they need local compute and storage. ROBO clusters can consist of just two nodes which reduces cost for licensing and hardware.

We will be using VMware vSAN on four 13th Generation Dell PowerEdge R630 vSAN ready nodes as our primary example of what a vSAN Cluster Looks like from a hardware and software vantagepoint. VMware recommends a minimum of three nodes for your primary production environment and strongly recommends a fourth node for maintenance. We selected a dual CPU configuration, however you can use single CPU nodes due to the resiliency and CPU power you get from multiple nodes. This is a great way to save money and get into an HCI solution if you have budgetary constraints.

Sample Configuration:

4 Node Dell R630, 1 Disk Group, All Flash, FTT1 (RAID 5 with 1 Parity), vSAN Advanced
CPUs - 2x Intel E5-2680v4 2.4GHz 14-Core CPUs
Memory – 12x32GB 2400Mhz RDIMMs
Cache Drive – 400GB 12Gbps SAS 2.5IN Write Intensive SSD
Capacity Drives - 3x 1.92TB 12Gbps SAS 2.5IN Mix Use SSD

The system above still can be scaled up by adding up to 4 more disks per node, either as a second disk group, or by adding 4 more capacity drives. Since this is an All-Flash cluster running vSAN Advanced, your data will be deduplicated and compressed, which means you will require less disk space and it will take longer to outgrow available disk space. Another benefit of vSAN is that your data is local to the compute, so your data doesn’t have to go from compute to switch to shared storage back to switch back to compute. This really gives vSAN All-Flash the advantage when it comes to performance compared with most SSD or NVMe based traditional shared storage systems with very few exceptions.

You can add another 12 RDIMMs of memory to each node of our sample config if you were to bring on workloads that require more memory. Should you need more CPU capacity, or you’ve run out of space for memory or disk, you can simply add another identical R630 node. The best part is the upgrades can be done quickly, and often non-disruptively. The elasticity of vSAN is a huge plus that many users really appreciate. For users with 4 or more nodes, they benefit from near zero downtime for maintenance!

*Current release is vSAN 6.7 Update 3.

Next Steps

Whether you need to refresh compute, storage, networking or all three at once, xByte Technologies has certified engineers to find the perfect solution for your requirements and budget. We also offer the latest in security, wireless, power & infrastructure, A/V collaboration, client computing, print/scan as well as many other technology solutions. Contact us today for a no cost evaluation and let us put our solutions expertise to work for you!

For more info on vSAN check out our latest webinar on demand: https://www.xbyte.com/hw/vmware-vsan.html

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