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.
