VMware administrators are in a tough position when a VMware HCL update threatens hardware support removal, but...
there are a few options worth exploring before breaking out the checkbook.
Almost all software vendors release a hardware compatibility list (HCL) that tells customers which hardware will work with new software versions. Vendors, including VMware, update the HCL with each major software version.
What options are available if your hardware is no longer on the VMware HCL? Most admins try to get as much life out of hardware as possible, but, eventually, all hardware falls off the VMware HCL.
Avoiding the upgrade is one of the easiest options. This requires staying at the supported version of the software until you can move off your old hardware. This isn't ideal, but it's a reasonable course of action. If you can live without the new features, security fixes and performance updates, holding off on the upgrade is reasonable.
This becomes a more significant issue if the vendor publishes end-of-life support. Normally, in this scenario, there's no option but to upgrade the software version and potentially retire the old equipment -- or continue without support.
The risk of going without support for production VMs is too great because an issue will inevitably occur and help won't be available. The vendor will have every right to refuse support for your environment despite a valid maintenance contract.
VMware HCL updates don't make outdated hardware useless
Noncritical test and development servers -- often considered disposable -- might give new life to these unsupported platforms. You can move noncritical workloads from supported software and hardware infrastructure to unsupported infrastructure. The need for temporary server space is always in demand. It might also be useful to test a few patches or work on some automation.
The additional space can be ideal for these types of tasks and, while running VMs on unsupported software and hardware might be risky, it can be efficient. The key is to make sure these VMs aren't essential because older, unsupported hardware and software doesn't offer stability.
Workarounds that enable you to install new software versions on hardware that is no longer on the VMware HCL are sometimes available online. Eventually, however, even a good workaround stops working. Update patches are especially good at breaking workarounds, so you'll inevitably face a lack of support again.
If this happens, there likely won't be enough time to wait for another blog post with a new workaround. If the vendor decides not to support a specific hardware platform, there's likely a good reason. Workarounds for small changes might be worthwhile, but core infrastructure often supports hundreds of VMs, so the stakes are much higher and the consequences dire.
The inability to upgrade is a difficult position to be in. Most of the actions taken to extend the life of software or hardware are costly due to a lack of vendor support and unpredictable consequences. Retiring a vSphere virtual farm is a fairly involved process because core infrastructure is costly to procure and doing so has a sizable effect on the data center.
Upgrades are a part of data center maintenance, as is the VMware HCL. Proper retirement plans are crucial because all equipment ages and software updates are inevitable.