Months ago. The development team was so focused on instruction result fidelity, machine state, and segment translation bypass issues that I/O subsystem did not receive the necessary attention. At least the tough part is done.
Gary Dennis Mantissa On 3/25/08 4:17 PM, "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> wrote: > Ummm, I may have missed something, but since when can you run Windows on > an IBM mainframe? > > Peter > > -----Original Message----- > From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On > Behalf Of Gary M. Dennis > Sent: March 25, 2008 17:14 > To: IBMVM@LISTSERV.UARK.EDU > Subject: Re: z/VM - Lightweight specific purpose file system > > The callable services benchmarks we conducted with BFS ran between 8 and > 10 > times longer than the test set running with the CMS file system. > > Assuming a cluster of 125 Windows(r) 2K z/VM guests and using I/O counts > generated by Win 2K on native Intel hardware the results of > extrapolating > the I/O overhead spooked us a bit. In effect, all our instruction > pipeline > optimization and translated instruction segment reuse optimization would > be > negated by the I/O overhead. > > We have a callable file system for z/OS that can handle an array of 128 > pools each containing up to 255 volumes each. That system would be a > bear to > convert owing to the OS-specific interface code but it appears from your > comments that converting may have to be seriously considered to achieve > the > desired results. > > Thank you. > > > Gary Dennis > Mantissa > > On 3/25/08 9:55 AM, "Alan Altmark" <[EMAIL PROTECTED]> wrote: > >> On Tuesday, 03/25/2008 at 04:26 EDT, "Gary M. Dennis" >> <[EMAIL PROTECTED]> wrote: >> >>> Is anyone aware of a VM open source file system port with some of the >>> characteristics listed below. Such a system might enable us to add > the >>> functionality needed to support these guests without starting at > zero. >> >> It isn't Open Source, but CMS has a POSIX file system (Byte File > System, >> BFS) that is managed by the SFS server, allocating space only as used. > I >> don't know that I would classify it as "lightweight", though from the > CMS >> user's point of view, it is, since the I/O takes place in the SFS > server, >> but it takes APPC/VM (IUCV on steriods) calls to make it happen. You > can >> talk to it in assembler using the BPX1xxxx callable services. It > could >> provide you a "jump start" while you develop your own file system. >> >> And just in case you haven't discovered it already, there's no > "pluggable" >> file system interface in CMS. You will need to write your file system >> from the bottom up. The only help CMS will provide to you is in the > form >> of HNDIO,HNDSVC, NUCEXT, and NUCXLOAD. >> >> Alan Altmark >> z/VM Development >> IBM Endicott >> > > > The information transmitted is intended only for the person or entity to which > it is addressed and may contain confidential and/or privileged material. Any > review retransmission dissemination or other use of or taking any action in > reliance upon this information by persons or entities other than the intended > recipient or delegate is strictly prohibited. If you received this in error > please contact the sender and delete the material from any computer. The > integrity and security of this message cannot be guaranteed on the Internet. > The sender accepts no liability for the content of this e-mail or for the > consequences of any actions taken on the basis of information provided. The > recipient should check this e-mail and any attachments for the presence of > viruses. The sender accepts no liability for any damage caused by any virus > transmitted by this e-mail. This disclaimer is property of the TTC and must > not be altered or circumvented in any manner. >
