/For=ForVolumeSpec /On=OnVolumeSpec /MaxSize=MaxSizeSpec - Resizes the maximum size for a shadow copy storage association ...

%1 %2 /For=ForVolumeSpec /On=OnVolumeSpec [/MaxSize=MaxSizeSpec]     - Resizes the maximum size for a shadow copy storage association between      ForVolumeSpec and OnVolumeSpec.  Resizing the storage association may      cause shadow copies to disappear.  If MaxSizeSpec is not      specified, there no limit to the amount of space it may use.  As certain      shadow copies are deleted, the shadow copy storage space will then      shrink.  MaxSizeSpec must be 300MB or greater and accepts the following      suffixes: KB, MB, GB, TB, PB and EB.  Also, B, K, M, G, T, P, and E are      acceptable suffixes.  If a suffix is not supplied, MaxSizeSpec is in      bytes.            Example Usage:  vssadmin Resize ShadowStorage /For=C: /On=D: /MaxSize=900MB