The ‘Export-SPWeb’ cmdlet provides a simple way of moving SharePoint content between sites. This command essentially exports all of your content into a series of .cmp files which can subsequently be re-imported to suit your requirements. If you want to dig deeper, you can even rename the files to .cab to expose the key Manifest.xml.
Last week I was exporting an entire site collection (don’t even ask why!) and the content database was around 85GB in size. The drive I was exporting too was 135GB but during the operation, it failed with Powershell reporting that there was ‘not enough space on disk’.
Having done some digging, I realised that the system drive was out of disk space due to that fact that during the export, all of the content appears to be copied to the ‘%USERPROFILE%\AppData\Local\Temp’ directory – which happened to be my system drive with only 40GB of space.
The fix is to remap the %Temp% variable to a drive with suitable space (restart is required)
And now I was able to successfully export the SharePoint content