Powershell: Script to purge old files from a folder

So I need to backup the SQL DB of a mission critical app.  The app sits on a virtual machine and backups need to get written to a NAS device.  But if there is a network or NAS issue then the backups won't get written, so no current backups.  What I do in this scenario is write the backups locally first, to c:\DB_backups, then script a task to sync the backup directory to the NAS.  If I have daily backups then the NAS will store all of the daily rolling backups, but that will eat up space on the C drive, which is bad.  So I need to purge the DB_backups folder, there are a few ways to do this and the easiest I found is to use powershell:

 Get-ChildItem 'C:\DB_Backup' -Recurse | Where {$_.creationtime -lt (Get-Date).AddDays(-10)} | Remove-Item  

This is pretty clever on powershell's part, lets step through what it does.

Get-ChildItem 'C:\DB_Backup' -Recurse

What this does is list all of the items in this folder as objects, and I am recursing through all of the folders in this folder, but that is not necessarily needed for this job.

Where {$_.creationtime -lt (Get-Date).AddDays(-10)}

The objects in this folder is then piped to this line.  Where is an alias for Where-Object.  We are using where because we only want to select files with specific attributes from this directory.  These attributes are defined by the $_.creationtime.  The creation time is then compared to today's date (Get-Date) using -lt (less than).  But we only want the files older than 10 days ago, so we subtract 10 from Get-Date, using the AddDays modifier.  So now we are listing all of the files older than 10 days, pretty neat, now to delete them.

Remove-Item

The cmd way of doing things is using del, which is actually an alias for -Remove-Item, neat.  This will remove the 10 day old objects we piped to it in the previous line.

Save it all as a .ps1 file and schedule the job in task scheduler to run daily to keep your C drive to size.