One of the requirements for successfully creating shadow copies of the volumes you intend to back up is having somewhere to put those shadow copies. If Microsoft's VSS is not given a place to put its shadow copies, shadow copy creation will fail. This article will outline the process for allocating shadow copy storage space for any volume you want to back up.
Windows Server Machines
Go to Start and then Computer to bring up a Windows Explorer view of the system. You should see the hard drives belonging to the machine listed (right).
Left-click on any hard drive once to select it then right-click on that drive. Select Configure Shadow Copies... from the right-click menu. This should bring up the Shadow Copies window.
In the Shadow Copies window, notice how, if the Used field is blank, there is no storage space currently allocated. Click on the volume for which you want to allocate shadow copy storage and hit Settings.
In the Settings window, you can choose which volume the storage area will be put on as well as the maximum size of the storage area. It is recommended you keep the storage area on the same volume as the source as well as have a maximum storage area size of 10% of the source volume. If you believe you need more space, you can increase the size further or set the maximum size to "No limit," however, if shadow copies are being made automatically by Windows or by another program, this may lead to the drive filling up with shadow copies. Once you have configured it to your liking, hit OK.
You should now see a "0 bytes on..." entry under the Used field. If you do, click on OK to finish the process.
Windows Desktop Machines
- Open an elevated command prompt window by using the combination Windows Key + R, typing cmd,and hitting the "Enter" key.
- Use the following command to change the shadow copy storage area:
vssadmin resize shadowstorage /on=x: /for=x: /maxsize=20%
/on" flag specifies where the shadow storage will be put, the "
/for" flag is the source volume of the storage, and the "
/maxsize" flag sets the maximum size for shadow storage area. More information on how to use this command is here.