Weird problem...we have a few 2821s that all were ordered with the Voice Bundle. My understanding is that by default, the 2821 comes with a single PVDM2-48 for 3 DSPs. Ordering the Voice Bundle gets you (2) PVDM2-32 for 4 DSPs.
What's odd is we have a 2821 showing only one PVDM2-32. This is happening both in the "show inv" and "show diag" commands.
Is it possible they might not be showing up due to a software problem, or are they indeed not present?
Cisco IOS Software, 2800 Software (C2800NM-ADVENTERPRISEK9-M), Version 12.3(11)T9
Have a look at the following;
Q. Do the Cisco 2800 and 3800 series routers ship with PVDMs?
A. No, PVDMs are optional components of each of these platforms, with the exception of voice bundles that have one PVDM included.
From this good doc;
We recently ordered two 2811's with the Voice Bundle and did have to order the additional PVDM's to accomodate our setup.
Hope this helps!