Most organisations do not run on cloud containers; they run on Windows Server, Active Directory and Hyper-V. This area is about keeping such environments predictable: Group Policy, virtualisation, event collection, and coexistence with newer platforms.
A log file more than ten times the size of the data file almost always means a database in the FULL recovery model without log backups. How log truncation works, what log_reuse_wait_desc shows and how to bring the .ldf file back to a sensible size in one go.
SQL Server Express has no SQL Server Agent and no maintenance plans, so backups have to be scheduled some other way. A PowerShell script with sqlcmd run from Task Scheduler under a gMSA, file retention, and restoring log backups on a second server as an equivalent of log shipping.
A SQL Server service account with a password that never expires and that several people know stays unchanged for years, because changing the password means downtime on every server. How to deploy a group managed service account (gMSA): the KDS root key, the account, installation on the servers and the account change in SQL Server Configuration Manager.
Error 26 after a server restart means the client could not determine the port of a named instance. Where the driver gets the name, port and protocol, when SQL Browser on UDP 1434 is needed, and why current drivers require a trusted server certificate.
Windows authentication in SQL Server keeps working when Kerberos fails, because the client silently falls back to NTLM. How the client builds the SPN, why a named instance needs a static port and its own DNS name, and how to check which protocol applications actually use.
A login lets a connection into the instance, a user grants access to a database, and the two are linked by a SID, not by name. How to build access from directory groups and custom roles, why an application should sign in with a Windows account, and how to fix a user without a login after restoring a database on another server.
Express has three hard limits: database size, buffer pool memory and the number of cores, and it has no SQL Server Agent, backup compression or high availability. How to measure which limit actually blocks work, how the SQL Server 2025 editions differ, and when to move to Standard.
A dynamic VHDX disk grows with every write to a new area, and deleting files in the guest does not shrink it. Where the growth comes from, how to reclaim space with TRIM and compaction, and how to configure the guest so the problem does not come back.
Forced password changes every 90 days and “upper case, digit, special character” rules are advice the standards have abandoned. What replaced them, how to check your current domain settings, and which MFA methods resist phishing.
The more everything depends on one sign-in point, the more you need access that does not. Cloud-only accounts with FIDO2 keys, a directory account with a split password, an alert on every use and a quarterly test.
A script run every night by Task Scheduler is a production service, even if it is a hundred lines long. How to write it so that a successor knows what it does and the scheduler knows whether it succeeded.
A directory nobody tidies collects accounts of people who have left, computers that no longer exist and permissions granted for a moment several years ago. The queries that reveal them, and a removal procedure that can be undone.
A domain administrator who logs on to a workstation leaves the key to the whole directory behind on it. Three tiers, separate accounts and a few user rights in Group Policy close that path without extra software.
A virtual machine checkpoint sits on the same storage as the machine, grows with every write and depends on its parent disk. How the AVHDX chain works, when a checkpoint makes sense, and how to find the ones that stayed too long.
A snapshot of a domain controller's virtual machine is not a directory backup. System state backups, the deleted object lifetime, the AD Recycle Bin, four ways to restore, and the stages of forest recovery when no working controller is left.
A central log system without a strategy becomes an expensive warehouse of noise. Which Windows events to collect, how to check that they are generated at all, how to filter and process them, and how long to keep them.
Group Policy and an endpoint management tool can set the same values, and when they do it at the same time the workstation flips between them. A responsibility map, the mechanics of the conflict and a clean-up of Group Policy Objects.
Containers have not replaced virtual machines, and the cluster itself runs on VMs. A decision table for typical workloads and the Hyper-V settings without which Kubernetes nodes lose memory, etcd consistency or quorum.