A VM DB2 server can indeed use CRR, but, (as far I know) not for DB2 applications running on VM. That is, DB2/VM uses CRR only when it used in DRDA mode from a remote site.
2007/11/28, Alan Ackerman <[EMAIL PROTECTED]>: > > On Tue, 27 Nov 2007 13:27:08 -0800, Schuh, Richard <[EMAIL PROTECTED]> wrot > e: > > >Are the warnings about Limp Mode if there is no CRR machine still > >extant? If so, there is still something being done by the CRR machine. > >When lightly loaded, I would not expect it to be a problem. > > > > > >Regards, > >Richard Schuh > > DB2 definitely uses CRR, and possibly other applications. There are CRR c > ommands that might tell > you something, although I have not tried them. > > Limp Mode is still documented in "z/VM V5R3.0 Performance". > > If the CRR server is not running, users who use SFS (and other resources > that participate in CRR) > are in a condition called limp mode. While in this condition, two-phase c > ommits are not possible. > Therefore, applications that use protected conversations or other resourc > es that do not support > simple commit logic cannot be run. A user may experience significant SFS > performance > degradation while in limp mode. To avoid limp mode, IBM strongly recommen > ds that every such > system have the CRR server running. The generation of a CRR server (VMSER > VR) and its associated > file pool (VMSYSR) are optional z/VM installation tasks. > > The question is, when are two-phase commits used? From what others have t > old you, one answer > is when you have R/W access to two different SFS filepools. > > Alan Ackerman > Alan (dot) Ackerman (at) Bank of America (dot) com >
