Prevent Volume Shadow Copies on removable media

We sell an integrated system, where we use a set of SSDs as exchangeable data storage. The system has a built-in Compact-Flash disk used for the OS (Windows 10) and several SSDs attached via SATA in removable enclosures that store recorded data.

The system works quite well, but since we're stressing the SSDs to their data rate limit, disk performance is absolutely critical. Now we observed that sometimes, the "System Volume Information" folder on the removable disks start growing and if that happens, the disks eventually become significantly slower. Reformatting the disks gets the performance back.

I wonder what these folders contain and whether there's anything useful in them? I actually think that Windows is writing backup information from the C: drive out there, although that would be completely pointless - the drives are later removed and eventually put into a different system or formatted before reuse.

  • Is there a way I can tell the Volume Shadow Service not to use these drives at all? vssadmin lets me configure a few things, but it doesn't seem possible to set the shadow size to 0 for a specific volume.
  • Or should I just completely disable the VSS service? What risks does that have? If the OS breaks, the standard procedure is anyway to re-flash it.

Among others, Windows uses the System Volume Information folder for System Protection, which will then track changes of files that Windows considers need protection.

Check in Control Panel > System > Advanced system settings > System Protection if Protection is enabled for the drives.

If it is enabled, then disable it.


To view the contents of the System Volume Information directory, using the PsExec utility:

  • Run PowerShell with SYSTEM privileges:

       "C:\path\PsExec.exe" -i -s powershell.exe
    
  • To view the contents of the folder, enter the command:

      Get-ChildItem 'X:\System Volume Information\'
    
  • The folder size can be found with:

      (Get-ChildItem 'C:\System Volume Information\' | measure Length -s).sum