2 Installing dbatools

This chapter explains how to get dbatools installed safely and reliably, and why that process teaches you the same skills you need for installing any PowerShell module. It starts with practical prerequisites and environmental considerations, then walks through execution policy and repository trust, how module auto-loading works, and why code signing matters. It concludes with preferred and alternative installation paths, ways to discover commands and documentation, and simple approaches to keeping dbatools up to date.

On requirements, dbatools is designed to work across a broad range of SQL Server versions and operating systems, with full support on modern Windows and substantial coverage on macOS and Linux. PowerShell 5.1 or later is recommended for performance and security; PowerShell 7+ (Core) runs most but not all commands. Many commands don’t require PowerShell on the target SQL Server at all, but OS-level tasks do rely on PowerShell Remoting (WS-Management over ports 5985/5986). Typical connectivity also involves the SQL Database Engine port (commonly 1433) and, for a small subset of tasks, WMI (135) and SMB (139/445). The chapter clarifies that execution policies are a safety mechanism, not a security boundary, and suggests RemoteSigned (or a process-scoped Bypass for advanced scenarios), explains policy precedence, and highlights the value of signed software and trusted publishers.

For installation, the preferred method is the PowerShell Gallery via PowerShellGet: set an appropriate execution policy, mark the PSGallery as Trusted with Set-PSRepository to avoid repetitive prompts, then install for all users (as Administrator) or for the current user only. Offline environments can use Save-Module on an internet-connected machine and copy the module into a folder on PSModulePath; zip-based installs from source are also possible but are unsigned and require a directory rename. The chapter shows how PowerShell’s module auto-loading and PSModulePath make commands readily available, offers guidance for finding and learning commands (Get-Command, Find-DbaCommand, Get-Help), cautions against loading dbatools alongside SQLPS/SqlServer in the same session, and recommends routine updates via Update-Module (or Update-Dbatools when not using the Gallery).

Figure 2.1. Configuration Manager, note the instance is offline but can still be modified

Figure 2.2. Trusted Sites

Figure 2.3. Microsoft’s PowerShell Gallery

Figure 2.4. The publicly available code signing certificate from dbatools

Figure 2.5. dbatools in temp directory

Figure 2.6. Twitter poll results

Figure 2.7. Unzipped directory, placed in valid modules path. Note the directory structure.

Figure 2.8. dbatools.io/commands, supporting both search and categories

Figure 2.9. docs website. Note that the most recent version can be found in the upper-left.

1. Find all commands that have DbaReg in their name.
   
2. Using Get-Help, find examples for the command Install-DbaInstance.
   

FAQ