How can I make my WSUS server download updates only when synchronizing?

Solution 1:

2 options to try, firstly as an example of how to have it set up. Synchronization Schedule is set to synchronize automatically at 9:00 PM, 1 synchronization per day.

Under Automatic Approvals – Advanced turn off automatically approve updates to the WSUS product itself and automatically approve new revisions of updates that are already approved.

Under Update Files and Languages - Update Files Tab tick "Store update files locally on this server" and untick "Download update files and to this server only when updates are approved".

The end result is that a synchronization will occur at about 9:00 PM each day, will pull down any new summary information and the associated update. This should get the end result you're looking for. Make sure you tweak Products and Classifications to only what you need.

Also you could try: Create a batch file that starts the service "update services". Create a batch file that stops the service "update services". Schedule a task to run each batch file at the appropriate times.

Solution 2:

I found a post from Lawrence Garvin at Technet, where he uses Group Policies to limit the bandwidth of BITS during working hours:

Configure the policy setting "Maximum network bandwidth for BITS background transfers" to limit the bandwidth consumption during your business hours. To achieve this set "Limit background transfer rate to =0= from =8am= to =5pm= At all other times Use all available unused bandwidth". Note, however, that this policy setting does not distinguish weekdays from weekends, so this will also limit throughput on Sat/Sun during daytime hours. Note also that the clients still will not be able to download during daytime hours due to the =0= setting. Ideally you'll determine what level of bandwidth on the WAN that you can allocate to the WSUS traffic, so that the clients can also use that available bandwidth during the day -- the significant point here being that the bandwidth throttling happens at the NIC, not only on the WAN.

You'll find this policy setting at Computer Configuration | Administrative Templates | Network | Background Intelligent Tranfer Service (BITS), and it's documented in Appendix E: Configuring BITS 2.0 and 3.0 for Download Performance of the WSUS Operations Guide.