IIS administration basics from PowerShell: sites, app pools, logs, and backing up the configuration

What it is

Two PowerShell modules manage IIS: the newer IISAdministration module (Get-IISSite, Get-IISAppPool, Get-IISConfigSection) reads and edits configuration through the same object model as IIS Manager, while the older WebAdministration module (native to Windows PowerShell 5.1; PowerShell 7 loads it only through the Windows PowerShell compatibility layer) adds convenience cmdlets such as Restart-WebAppPool, Start-WebAppPool, and Stop-WebAppPool that the newer module does not directly duplicate. Get-IISSite lists sites and their bindings and state; combining both modules in a script is normal on Windows Server. Outside PowerShell, appcmd.exe (in %windir%\system32\inetsrv) remains the command-line tool for configuration tasks including backup.

Why it matters

An application pool holds a site's worker process; recycling it (by default an overlapped restart: a new worker process starts and takes new requests while the old one finishes its current ones) clears memory leaks and picks up some configuration or code changes without a full IIS restart. IIS's own periodic-restart recycling settings can trigger this automatically on a schedule, a memory threshold, or a request count, configured through the <recycling> element of applicationHost.config. IIS writes W3C-format request logs by default to %SystemDrive%\inetpub\logs\LogFiles, organized into per-site subfolders — the first place to check for 4xx/5xx patterns or unexpected traffic, and a location that fills a system volume over time if never rotated or moved. Because most IIS-wide configuration lives in one file, applicationHost.config, a bad edit can affect every site on the server at once; appcmd add backup "<name>" captures a restorable copy of that file (and related server-wide state) before an agent makes a manual edit.

How to apply

• Enumerate sites and pools before changing anything: Get-IISSite | Select-Object Name, State, Bindings and Get-IISAppPool | Select-Object Name, State.
• Recycle rather than fully restart when only the worker process needs a reset: Restart-WebAppPool -Name "DefaultAppPool".
• Take a named configuration backup before an applicationHost.config edit: run appcmd add backup "before-change" from an elevated prompt in %windir%\system32\inetsrv; restore it later with appcmd restore backup "before-change" if the edit needs to be undone (the restore replaces the whole server configuration, including changes made after the backup).
• Point log collection or log shipping at %SystemDrive%\inetpub\logs\LogFiles by default, and confirm the actual configured path per site, since it can be redirected.

Pitfalls

• Assuming Restart-WebAppPool exists in the IISAdministration module — it is a WebAdministration cmdlet; with IISAdministration alone use (Get-IISAppPool -Name "DefaultAppPool").Recycle() or the Get-IISServerManager object approach.
• Forgetting that an appcmd backup does not include site content, only server-wide configuration state — pair it with a real content backup.
• Letting logs accumulate unmanaged on the system volume; set retention or move the log directory rather than discovering the disk is full during an incident.