Adequate Maintenance Windows - Windows Updates - Need advice

[omniblue]

First let me state my understand of deploying updates and maintenance windows.

 

• Updates will download to clients as soon as the availability is met in the deployment and the client is receiving such deployment and found to be needed by the client. The client does not wait for deadline expiration or maintenance window to cache the updates for later installation during a maintenance window
• Updates are scheduled by the client to install during the maintenance window, per update, at specific times within the maintenance window - for EACH individual update. Follows a 20m install time + 5m restart warning + 10 minute restart turnaround for 35m total.
• If you have 20 updates to install and only a 5 hour maintenance window. 300/35=8. Only 8 updates will be installed.

 

Here is my case scenario:

 

• Monthly Patch Deployment to 1500 clients.
• There is a single maintenance window, Sunday 00:01 - 07:00 for all 1500 clients.
• The Update deployment is configured to be available 4 days ahead of the deadline/maintenance window, Tuesday 00:01. Workstation restarts are permitted. The deadline occurs on Saturday 00:01, 24 hours before the Maintenance window beings on Sunday 00:01-07:00
• BITS is not throttled. Assume in this case, no issues related to network traffic exist.
• For the sake of the conversation, all SCCM clients are online and functional.

 

Where I need help...

Is the 7 hour window enough to install updates for 1500 clients?

 

I'm concerned this may not be enough time as I am not concrete on how update installs behave during the MW. I am also unsure how updates are installed exactly during the maintenance windows; specifically if they install as fast as possible or if the client scheduler sets a installation time for each individual update before the maintenance window starts and sticks to it. Let me give you an example.

 

• 50 updates need to be installed by the client.
• 7 hour maintenance window starting at 00:01 ending 07:00
• Deadline has already expired 24 hours ago.
• It's now 1 hour into the MW and the first update is now being installed

 

If this update installs in 5 minutes, and no restart is needed, will the next update start to install immediately and execute as quickly as possible, where subsequent updates continue just the same? Installing as quickly as possible until all are completed or the MW is within 34 minutes of expiring? Does the client instead wait the remaining 30 minutes before the next update installation begins?

 

You thoughts are greatly appreciated.