Initial commit - this does work

createvsc.vbs

+Set objFSO=CreateObject("Scripting.FileSystemObject")
+Const VOLUME = "C:\"
+Const CONTEXT = "ClientAccessible"
+outFile="C:\vscbackup\vsc.id"
+
+Set objFile = objFSO.CreateTextFile(outFile, True)
+ 
+strComputer = "."
+Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
+Set objShadowStorage = objWMIService.Get("Win32_ShadowCopy")
+errResult = objShadowStorage.Create(VOLUME, CONTEXT, strShadowID)
+
+objFile.Write strShadowID
+objFile.Close
+
+Set colItems = objWMIService.ExecQuery("Select * from Win32_ShadowCopy")
+For Each objItem in colItems
+	If objItem.ID = strShadowID Then
+		strDeviceObject = objItem.DeviceObject
+		arrDeviceObject = split(strDeviceObject, "\")
+		strVSCOut = arrDeviceObject(UBound(arrDeviceObject))
+	End If
+Next
+
+Wscript.Echo strVSCOut
+
+Wscript.Quit 0

log

+{70E020EF-152C-4449-834E-0742AB7011C5}
+vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
 (C) Copyright 2001-2005 Microsoft Corp.
 
 Error: Invalid option.
 
 Delete Shadows /For=ForVolumeSpec [/Oldest] [/Quiet]
 Delete Shadows /Shadow=ShadowId [/Quiet]
 Delete Shadows /All
 - For the given ForVolumeSpec deletes all matching shadow copies. 
 If /Oldest is given, the oldest shadow copy on the volume is deleted
 If /All is given, then all shadow copies on all volumes that can be 
 deleted will be deleted. If /Shadow=ShadowId is given, the shadow copy 
 with that Shadow Copy ID will be deleted. Only shadow copies that have 
 the ClientAccessible type can be deleted.
 - The Shadow Copy ID can be obtained by using the List Shadows command.
 When entering a Shadow Copy ID, it must be in the following format:
 {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX} 
 where the X's are hexadecimal characters. This ID can be obtained 
 through the List Shadows command.
 
 Example Usage: vssadmin Delete Shadows /For=C: /Oldest
+{70E020EF-152C-4449-834E-0742AB7011C5}
+/cygdrive/c/Windows/system32/vssadmin delete shadows /ShadowID\={70E020EF-152C-4449-834E-0742AB7011C5} /Quiet
+{70E020EF-152C-4449-834E-0742AB7011C5}
+/cygdrive/c/Windows/system32/vssadmin delete shadows /ShadowID={70E020EF-152C-4449-834E-0742AB7011C5} /Quiet
+vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
 (C) Copyright 2001-2005 Microsoft Corp.
 
 Error: Invalid option.
 
 Delete Shadows /For=ForVolumeSpec [/Oldest] [/Quiet]
 Delete Shadows /Shadow=ShadowId [/Quiet]
 Delete Shadows /All
 - For the given ForVolumeSpec deletes all matching shadow copies. 
 If /Oldest is given, the oldest shadow copy on the volume is deleted
 If /All is given, then all shadow copies on all volumes that can be 
 deleted will be deleted. If /Shadow=ShadowId is given, the shadow copy 
 with that Shadow Copy ID will be deleted. Only shadow copies that have 
 the ClientAccessible type can be deleted.
 - The Shadow Copy ID can be obtained by using the List Shadows command.
 When entering a Shadow Copy ID, it must be in the following format:
 {XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX} 
 where the X's are hexadecimal characters. This ID can be obtained 
 through the List Shadows command.
 
 Example Usage: vssadmin Delete Shadows /For=C: /Oldest
+{70E020EF-152C-4449-834E-0742AB7011C5}
+/cygdrive/c/Windows/system32/vssadmin delete shadows /Shadow={70E020EF-152C-4449-834E-0742AB7011C5} /Quiet
+vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
 (C) Copyright 2001-2005 Microsoft Corp.
 
+vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
 (C) Copyright 2001-2005 Microsoft Corp.
 
 No items found that satisfy the query.
+vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
 (C) Copyright 2001-2005 Microsoft Corp.
 
+vssadmin 1.1 - Volume Shadow Copy Service administrative command-line tool
 (C) Copyright 2001-2005 Microsoft Corp.
 

post_backup.sh

+#!/bin/bash.exe
+
+shadowid=$(< /cygdrive/c/vscbackup/vsc.id)
+cmd="/cygdrive/c/Windows/system32/vssadmin delete shadows /Shadow=$shadowid /Quiet"
+echo $($cmd) >> /cygdrive/c/vscbackup/log
+rm /cygdrive/c/vscbackup/vsc.id
+rm /cygdrive/c/vscbackup/vsc

pre_backup.sh

+#!/bin/bash.exe
+
+winpath="C:\vscbackup\createvsc.vbs"
+vsc=`cscript.exe //nologo $winpath`
+echo $vsc
+vsc=`echo $vsc | tr -d '\r'`
+ln -s /proc/sys/Device/$vsc/ /cygdrive/c/vscbackup/vsc

schtask_cleaner.sh

+#!/bin/bash.exe
+
+/cygdrive/c/Windows/system32/schtasks /run /tn BackupPC-VSC-Cleaner

schtask_starter.sh

+#!/bin/bash.exe
+
+/cygdrive/c/Windows/system32/schtasks /run /tn BackupPC-VSC
+
+while [ ! -h /cygdrive/c/vscbackup/vsc ]
+do
+  sleep 2
+done