By High availability architectures are built on a single promise: when the primary system fails, the secondary takes over without disruption. But that promise breaks down quietly, over time, through a process most infrastructure teams never actively monitor — configuration drift. Disk space gets added to the primary and forgotten on the backup. Admin rights get updated on one node and not the other. Startup types get reconfigured on System A while System B remains frozen in an older state.
By the time an outage forces a failover, these small, accumulated mismatches become critical failures. The secondary system, which was supposed to be a seamless replica, is no longer capable of taking over the applications it was designed to protect. And it is only in that moment — under the pressure of a real incident — that teams discover the gap existed at all.
This is the core problem that SIOS Technology’s high availability health check program is designed to solve. Rather than waiting for an unplanned event to expose configuration inconsistencies, the health check process — conducted either as a live, screen-share-based system walkthrough or as an asynchronous log review — validates that every node participating in an HA solution is genuinely ready to assume responsibility for critical workloads.
The concept is straightforward, but the operational discipline required to maintain it is where most organizations fall short. Primary systems receive constant attention: capacity expansions, permission changes, service reconfigurations. Secondary systems, by their nature, receive far less. Over weeks and months, the gap widens. The health check exists to close it before it becomes an incident.
The urgency is not theoretical. Deferring a health check to the next quarter, or the next fiscal year, means crossing your fingers and hoping nothing breaks in the interim. For organizations running critical applications on platforms like SIOS Lifekeeper, that is not a risk management strategy — it is an absence of one.
The Guest: Trey Isaac, Sr. Product Support Engineer at SIOS Technology
Key Takeaways
- HA health checks can be conducted live (screen-share walkthrough of both nodes) or asynchronously (log submission and manual review) — both are valid and effective approaches.
- The most common gap uncovered in first-time health checks is configuration drift: primary and secondary nodes that are no longer identical, making failover unreliable.
- Specific drift patterns include mismatched disk space allocations, inconsistent admin rights, and incorrectly configured service startup types on the secondary node.
- Deferring health checks to a future quarter increases unmitigated outage risk and removes the peace of mind that HA infrastructure is supposed to provide.
- SIOS frames the ideal HA node relationship as “identical twins” — any deviation from that standard is a potential failure point during a real disaster recovery event.
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Read Full Transcript & Technical Deep Dive
In this exclusive interview with Swapnil Bhartiya at TFiR, Trey Isaac, Sr. Product Support Engineer at SIOS Technology, explains how high availability health checks work in practice, what the most common vulnerabilities look like inside real HA environments, and why organizations should treat health check cadence as a non-negotiable operational discipline rather than a deferred project.
What a High Availability Health Check Actually Looks Like in Practice
For many infrastructure teams, the concept of an HA health check is understood in theory but undefined in practice. Trey Isaac brings specificity to the process, describing two concrete methodologies that SIOS uses with customers — one synchronous and one asynchronous — both aimed at validating that every system participating in an HA solution is genuinely ready to take over under real conditions.
Q: Can you walk us through how a quick HA health check looks in practice — how teams put it in place and how it checks whether everything is working fine for high availability and disaster recovery?
Trey Isaac: “A quick health check can be a number of ways. It can actually be a live, quick high availability health check where we actually do some type of screen share with you, we get on your systems, and we go through whatever important application that you’re hosting. We make sure that looks good on System A and then we do the same concept on System B. Live, we go through, open up the application, making sure everything looks good. Operating systems, we go through making sure your services are configured correctly, we make sure your storage is configured correctly, you have your processes set to the right startup types, everything. So you could do a live version and then you can do a non-live version where you just send us all the logs from all the systems that are going to be part of your HA solution and we just manually go through all your logs to make sure they match up properly. So it’s a number of ways to attack it. Those are just the first two that come to mind.”
Why Now Is the Right Time to Prioritize HA Health Checks
Infrastructure complexity has increased, cloud adoption has introduced new layers of dependency, and the cost of unplanned downtime continues to rise. Against that backdrop, treating HA health checks as an optional or deferrable activity carries compounding risk. Trey Isaac frames the urgency in direct, operational terms: the only way to have genuine confidence in your HA environment is to verify it now, not at some future point on a planning calendar.
Q: Why is now the right time for organizations to prioritize HA health checks? What has changed in terms of infrastructure complexity, cloud adoption, or outage risk?
Trey Isaac: “What I like to tell people is starting a routine starts now. You don’t want to just keep kicking a can down the road and saying, ‘I’ll do a health check next quarter’ or ‘I’ll do a health check next fiscal year,’ because at that point you’re just crossing your fingers hoping nothing happens until next quarter or next year. You’ll never be able to get a true peace of mind if you don’t just start doing your health check now and making sure that if something bad happens — an unforeseen event happens — all systems participating in your high availability solution like Lifekeeper are ready to take over and do their job.”
The Most Common Gaps Uncovered in First-Time HA Health Checks
When SIOS engineers conduct a health check on a customer environment for the first time, a consistent pattern emerges: the primary and secondary nodes are not as identical as the team assumed. The “identical twins” model — where both nodes mirror each other exactly in terms of disk, permissions, services, and configuration — is the standard that HA solutions like SIOS Lifekeeper depend on. In practice, operational shortcuts quietly erode that parity over time.
Q: What are the most common gaps or vulnerabilities you typically uncover when customers run an HA health check for the first time?
Trey Isaac: “With the high availability health checks I have done, whenever I’m working with someone, I like to tell them: just think of all the systems that are part of your high availability solution like Lifekeeper as siblings. And you want those siblings to be identical twins. What tends to happen is you have your main system that’s hosting everything and it gets all the love, per se. If you need more disk space, you’ll add it to that main system and forget to do it on the backup system. If you have to change some type of admin rights, you might change the admin rights on the main system and just forget to do it on the backup system. So a lot of times what we uncover is that the systems are not identical twins. And when the first system goes down, things are not going to work properly on the second system.”
Watch the full TFiR interview with Trey Isaac here
