[wpkg-users] WPKG + Wireless Laptops

[Matthew Gyurgyik]

On 02/02/2012 04:18 PM, Alan Adams wrote:
> You've picked up one of the biggest problems with respect to deploying
> software to laptops. In general they are only turned on and connected
> to the network when the users want to work on them, and pushing
> software out to them in the background can cause problems.
>
> It is a particular problem in schools. A typical scenario is that of
> 30 children collecting laptops, taking them to the classroom and
> switching them on. At this point there is a lot of network traffic
> associated with Group Policies being deployed. As soon as the login
> window appears they enter their credentials, and there is another
> burst of GPO traffic.
>
> Somewhere in the middle of this wpkg starts downloading the 45MB MSI
> of Adobe Reader. Not content with that, it uninstalls the previous
> version, so it downloads that MSI as well.
>
> You've now got 30 laptops downloading 100MB of data each across, in
> the best case, 2 33Mb/sec wireless shared links. 30,000 mbits, through
> 66mbit/sec is 500 seconds, about ten minutes, ADDED to the normal
> startup and login time. Add the contention and retransmission overhead
> when the wireless gets saturated, and it can, and does, take an hour
> before the last pupil is logged in and ready to work.
>
> Primary school lessons are typically 25 minutes.
>
> Now I can see a way in the long term to reduce that. The wpkg script
> will copy the msi to a location on the hard drive, then run the
> msiexec command referencing the copy. No improvement this time round,
> but when it comes time to uninstall, it doesn't need to copy the msi
> again. That should give a factor two improvement. It will also help in
> deploying patch versions. To deploy 10.1.2 you deploy the 10.1.0 msi
> accompanied by the 10.1.2 msp. Combined, 65M. However the msi for
> 10.1.0 would already be on the computer.
>
> It also avoids the problem I've got at the moment. I deleted the Adobe
> reader 9.4.0 msi, then discovered some computers needed it for the
> uninstall when I deployed 10.1.2. (I don't know why they didn't get
> 10.0.0, 10.1.0 etc...) This means that I now cannot deploy 10.1.2 to
> those computers, because the uninstall part of the process fails.
> Setting the flag in 10.1.2 not to uninstall doesn't help, because it
> simply refuses to install as another version is present.
>
> I had to deploy Number Shark 4 last week. The msi is 450MB. Using
> wired connections it took around 15 minutes. Those using wireless,
> only 4 at a time, took almost an hour. Fortunately that school only
> has 30 laptops, so I managed to finish in a day. I had to pre-arrange
> that there would be no laptops available for the whole day though.
>
> i have been hoping I could use wpkg, running as a service, to allow
> deployment during lessons. Using AD deployment simply prevents the
> lesson from starting. (I only have one day every 3 weeks in each
> school, so doing it out of normal hours is generally not possible.)
> However the issues described above are making me think it still isn't
> going to work.
>
I appreciate your in-depth reply. It has brought up a lot a valid and 
helpful points. We are dealing, currently, with 4 laptop carts each 
containing 24 laptops. We have longer class periods (90 minutes). Just 
to deploy Firefox (10MB) to a set of laptops would take 45 seconds 
assuming ideal conditions (54Mbps). We have Wireless N access points, 
but realistically we likely wouldn't come close to that with all 24 
clients connected.

 From boot to login, it takes about 2-3 minutes. To add much more time 
to the login process would be frowned upon. Maybe, the best solution in 
this case would be to manually run wpkg from each machine to fetch new 
updates/software. Alternatively, I might be able to create an AD user 
that has a login script to call wscript. This way I could give said 
username to a few staff to help with this process.