Windows operating systems

Volume Shadow Copy Services tuning

Edit online

Several fixes for Microsoft Volume Shadow Copy Services (VSS) tuning are available if you are experiencing difficulty with VSS tuning.

Controlling the VSS diff area size

After you apply these fixes, one of the following events occurs:
  • The shadow copy of volume C: took too long to install
  • The shadow copy of volume C: was stopped because the diff area file could not grow in time.

Reduce the I/O load on this system to avoid these problems. If the events still occur, use the following registry key to control the size of the diff area used by VSS:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VolSnap\MinDiffAreaFileSize : REG_DWORD: <size in MB> (the default size is 300, but can be increased to 3000).

Event log maximum size

Microsoft indicates that if the event logs are sufficiently large, the copy operation can take longer than the timeout for systems with high I/O load or high memory load. The log size is best when less than 64 MB.