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Category: Backups

T-SQL Snapshot Backups on Hyper-V

Published 2026-05-11 by Kevin Feasel

Anthony Nocentino takes a backup:

If you’ve been following my T-SQL Snapshot Backup series, you’ve seen this technique work on bare-metal and standard VM deployments where database files live on volumes directly presented to the SQL Server OS. In this post, I’m bringing T-SQL Snapshot Backup into a Hyper-V cluster environment, with database files on VHDXs backed by a Pure Storage FlashArray Cluster Shared Volume (CSV). Hyper-V adds a few extra layers to manage at the hypervisor level, but the SQL Server side of the story is identical. Let’s walk through it.

Click through to see how it all works. It has taken me a long time to accept the idea that storage volume snapshots could fit the bill, and it’s been people like Anthony, Andy Yun, and Mark Wilkinson who have allayed my concerns over the years.

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Testing Your SQL Server Backups

Published 2026-04-24 by Kevin Feasel

Vlad Drumea stresses the need to test:

Folks think that if they just take backups regularly, and their backup intervals match their recovery point objectives, then they can rest assured knowing (more like falsely thinking) they have backups from which to restore in case something bad happens to a database or to the entire instance.

Yeah, there are several things that can go wrong, even beyond the solid answers Vlad provides. Think about developers taking one-off backups that break the log chain, overly-aggressive purge processes that delete backups before they’re fully moved to long-term storage, etc.

Definitely check out Vlad’s post. If you’re interested, I also have a video series on YouTube that covers SQL Server backup and restore.

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Explaining Non-Yielding Schedulers during Backups

Published 2026-03-25 by Kevin Feasel

Sean Gallardy provides an explanation:

Sparked by my friends at Straight Path SQL, we’re going to look at a rare cause of non-yielding scheduler dumps. This is another one of those items that I meant to write about a long time ago when I worked in Support and then, well, I suck and clearly forgot about it. This should give you an idea of how rare this specific issue hits.

Read on to see what might cause this scenario and why you’re likely never to see it in the wild.

Though now that I’ve typed it, I’m sure someone will take that as a challenge.

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Restoring Backed-Up Items in Microsoft Fabric

Published 2026-03-05 by Kevin Feasel

Gilbert Quevauvilliers grabs an item from backup:

In my previous blog post I had shown you how to backup your Microsoft Fabric Items: Backing Up Your Microsoft Fabric Workspace: A Notebook-Driven Approach to Disaster Recovery – FourMoo | Microsoft Fabric | Power BI

The next natural question is what happens when you want to restore one if the items that were previously backed up.

In the steps below I will show you how to do this.

Read on to see how it works and a bit of pain that you might experience.

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Backup Updates in SQL Server 2025

Published 2026-03-02 by Kevin Feasel

AK Gonzalez summaries some changes:

For years, database professionals faced a frustrating limitation. With Availability Groups, you could offload some workloads to secondary replicas—but not your real backup strategy.Yes, you could run copy-only backups on a secondary. But true full backups? Differential backups that maintain the LSN chain? Those had to run on the primary replica, until now. SQL Server 2025 introduces the ability to run true full backups and true differential backups on secondary replicas.

Read on to see what this means. AK also looks at the change to ZSTD for backup compression and immutable backups in Azure Storage.

One thing I would want to warn anybody (or any company) looking into using immutable storage for backups is, Microsoft’s not joking about that immutability. That includes deleting them when you see what the bill is going to be. You can set retention polices to delete these automatically, but that’s the only way you’re getting rid of those old backups. And just because they’re old doesn’t mean you get charged less for the privilege of storing them off-site.

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Data Correlation Optimization and Cross-Database Data Leaks

Published 2026-01-08 by Kevin Feasel

Fabiano Amorim shows off a vulnerability:

This vulnerability involves restoring a database into a DBaaS and uses a “corrupted” internal view, effectively turning the engine’s own intelligence against itself.

The exploit is elegant in a disturbing way, since there’s no need for xp_cmdshell, CLR, or any of the usual suspects – just a carefully crafted .bak file and SQL Server’s unwavering belief in its own metadata integrity.

The payload hides where no DBA would look – system tables that are supposed to be immutable – and executes under a context that was never meant to be controllable by the user.

This is not a misconfiguration or a permission trick – it’s a design flaw rooted in how the SQL Server engine trusts its persisted metadata, and how that trust persists across the boundary between a user-managed instance and a cloud-managed environment.

This kind of fits in the “Neat, but not incredibly practical” bucket for me, so I can understand Microsoft marking this as a low-risk security issue.

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Expiring Old Postgres Backups with pgBackRest

Published 2025-12-17 by Kevin Feasel

Stefan Fercot demonstrates some new functionality in a tool:

A useful new feature was introduced on 11 December 2025: Allow expiration of the oldest full backup regardless of current retention. Details are available in commit bf2b276.

Before this change, it was awkward to expire only the oldest full backup while leaving the existing retention settings untouched. Users had to temporarily adjust retention (or write a script) to achieve the same result. Expiring the oldest full backup is particularly helpful when your backup repository is running low on disk space.

Let’s see how this works in practice with a simple example.

Click through for the example.

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Backup and Recovery versus Disaster Recovery

Published 2025-12-12 by Kevin Feasel

Brendan McCaffrey draws a distinction:

It surprises me how many people treat “disaster recovery” and “backup & recovery” as interchangeable terms. But backups are not disaster recovery, and disaster recovery is not a backup strategy. Confusing the two creates a false sense of security that often becomes visible the moment something goes wrong. The goal of this post is to offer clarity on what separates these concepts, so you can design a strategy that actually protects your business, not just your data.

Read on for Brendan’s argument.

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Backups on Secondary Replicas in SQL Server 2025

Published 2025-12-03 by Kevin Feasel

Brendan McCaffrey takes a look:

Back in 2022, I wrote a post called SQL Server Backups on Secondary Replicas: Best Practice or Bad Idea? At the time, the limitations were clear: backups on secondaries were restricted, operationally risky, and often misunderstood.

Three years later, SQL Server 2025 has expanded what you can do on a secondary replica. Some of these changes are genuinely great. But the question I keep getting is:

Does SQL Server 2025 finally make backups on secondary replicas a best practice?

Read on for the answer.

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Changes to Backups in SQL Server 2025

Published 2025-11-12 by Kevin Feasel

Steve Jones notes one interesting change to backups in SQL Server 2025:

I’ve been a DBA (or Ops manager) for quite a bit of my career, and one of the things I’ve thought was top priority was backups. I always want to be sure I have a recovery strategy, because if I don’t, nothing matters. Things go wrong and systems fail and I need to protect systems.

Security is a close second, but backups really matter.

Something else backup-related that Steve doesn’t mention is the new form of backup compression using ZSTD. Initial testing of this has been fairly positive and I think it’s worth trying it out as well.

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