On a smaller primary drive, the saved downloaded files from previous updates can take up substantial disk space and interfere with major OS upgrades. Case in point is a recent Windows 10 feature update requiring 20 GB of free disk space with a minimum of 8GB free on the primary drive. In the MinisForum Z83 units we have, the SSD is 30 GB. Obviously the update cannot be installed without an additional drive.
Substantial space can be saved by moving the c:windowssoftwaredistribution folder to another drive. For this example we’ll use D:UpdateDownloadFolder. However, the permissions must also be moved to the new folder otherwise updates will fail. The alternative is to move it to an xFAT32 formatted disk and permissions are irrelevant.
There are 3 ways permissions can be moved: ICACLS, Get-ACL & Set-ACL, or robocopy. For some reason the first 2 do not work on our machines with the Intel Atom processor; they will reset the permissions to default, everyone full control, rather than update. The commands work on other machines with different processors. Also, it’s not a version issue as they fail on both the 1803 and 1903 versions on the Atom processor.
Moving the folder is simple but has a couple of gotchas. The log file may be open in a process and refuse to close even if you stop the windows update service. Simple fix is to disable the Windows Update service in service manager, which appears as WUAUSERV in task manager services list, then reboot. Remember to enable it when finished.
For robocopy the command is:
robocopy c:\windows\softwaredistribution d:\UpdateDownloadFolder /MIR /SEC.
If the log file is open, it will create the UpdateDownloadFolder then complain about an open file. You can use CTL-C to halt the copy. At this point, the base folder has the correct ACLs and there is no need to finish the copy process as update will create the subfolders as needed. However, you still have to close the open file in order to finish the redirect.
The get/set is very simple but it just doesn’t work in some instances. Create the new file then the command is:
Get-ACL c:windowssoftwaredistribution | Set-ACL d:UpdateDownloadFolder
ICACLS is a little tricky because of the folder name change.
Commands are:
ICACLS C:windowssoftwaredistribution /save c:moveacls.txt
The folder name has to be changed in the saved ACL file, then it will work. Open the file with text editor and change the file name from softwaredistribution to UpdateDownloadFolder.
ICACLS D: /restore moveacls.txt
Note: restore in the root directory. If you try to restore in the folder it will fail. The program is looking for the matching subdirectory in its header.
To check permissions on the new folder you can use:
ICACLS D:UpdateDownloadFolder | format-list
or
Get-ACL D:UpdateDownloadFolder | format-list
To finish the move, you need to rename the softwaredistribution folder to softwaredistribution.old then create a link to the new target directory. Use mklink which works only in Admin mode CMD prompt, not in Powershell.
The command is:
mklink /j C:\windows\softwaredistribution D:\UpdateDownloadFolder.
To remove the link, just delete it.
Test the change by checking for new updates. If permissions and links are not set correctly it will quickly fail. Once it’s successful, you can safely delete the C:windowssoftwaredistribution.old file.
Jerry's blog 