I have seen similar things.  You have to put on 4.2.2 to correct this
problem.  However, a recycle of the dsmserv will fix the problem.  The issue
manifests itself in several ways.  I have only seen the problem once.  I am
still on 4.2.1.15 which partially fixes the problem.  The problem is caused
by a bunch of idle drives dismounting at the same time.  Apparently, there
were some threading of updates to instorage control blocks that get hosed.

Paul D. Seay, Jr.
Technical Specialist
Naptheon, INC
757-688-8180