Here is an interesting and very helpful post from Matt Shadbolt.
In this post he talks about the I/O performance issue faced on his lab environment. This issue could happen in our production environment as well if we don’t have proper design in terms of storage (Disk/Lun/NAS).
One more important point he mentioned in the post is about the average disk queue length. We need to take care of this also at the time of design.
Microsoft best practice for ConfigMgr is for all disk queue lengths to be < 2
Another highlight of his post is ConfigMgr 2012 CAS behavior while deploying packages to other DPs (even if our CAS doesn’t have a DP role)
A lot of people don’t realize that we actually have an SCCMContentLib on our CAS, even if we don’t have a DP on that site system. The SCCMContentLib on a CAS is used a little differently. It isn’t there for clients to access content, is there for Distribution Points to access content. So when I added an OSD WIM image to a DP, it’ kicked off the local processing of the WIM into the local SCCMContentLib.
When you add a package to a DP for the first time, Distribution Manager on the CAS will take a snapshot of the source
Read the Full Post @ ConfigMgrDogs (TechNet Blogs)