Thanks, Martha. Running DB2 for VM with plenty of other load is the main exposure, as the behavior which triggers the problem (contact me directly if you want the gory details) is quite unusual and unique to DB2, as far as we know. There's a small possibility of hitting it while running a Linux th at exploits the Diagnose x'10' page release "ballooning" device driver hack,
but I doubt many folks run with that (I'm not even sure of its proper nam e or whether it ever made it into any distro). Once it starts happening, o f course, the hang behavior starts spreading to other users, as the DB2 machines (or user machines trying to talk to it) almost invariably hold s ome other serialization when they hit the hang. We'll be watching customer experience with the circumvention as well as doing ongoing investigation to determine whether it's an appropriate permanent solution (I hope it is, a s the alternative fixes are a lot more complicated). The only concern we h ave with the circumvention isn't functional, it's the potential impact on performance of holding a share of one of the locks involved (VMDPTIL) for a longer duration. - Bill Holder, z/VM CP Development, Storage Management
