Marcy, avoid large disk images for Linux under VM unless it is very low I/O type data. VM does NOT support PAV, MVS does. The only way MVS will support the large dasd with reasonable performance is because of PAV - we don't have it. So if you can, ask for 3390-1 or 3390-3. At this point, I believe that LVM across small DASD is better than using large dasd.
For your focus job, change MDC to record cache. Record cache was put back in VM (after being taken out) almost specifically for FOCUS I/O performance problems. Linux should use record cache as well. the default track cache i think was designed to create performance problems for cms and linux.... >Date: Thu, 3 Apr 2003 13:23:56 PST >From: Marcy Cortes <[EMAIL PROTECTED]> > >I realize that this request is somewhat like asking you all what >color looks best on me when you've never seen me in person.. but >here goes anyway. > >My knowledge about DASD technology is pretty dated. We've >usually just been given whatever os/390 is finished with, which, >to be honest, has usually been adequate here for VM needs >(although we do have an i/o bound FOCUS job that is having >trouble meeting it's deadline that must be addressed too). > >Now we've been asked to put together a list of what Linux on VM >might need in terms of DASD. Our situation so far has been build >it and they will come. They are starting to come (we have 13 or >so Linux guests now) but don't have a grand scheme of replacing >the world (yet :). So far, we're mainly doing apache and another >app which uses mysql. > >So what would you ask for if you didn't know what you needed and >wanted to be prepared:) Our MVS environment has moved to all mod >9, mod 27, and FICON. Are these well suited to Linux? How about >remote copy support (we do run our disaster recovery in house). > >Marcy Cortes >Wells Fargo Services Co "If you can't measure it, I'm Just NOT interested!"(tm) /************************************************************/ Barton Robinson - CBW Internet: [EMAIL PROTECTED] Velocity Software, Inc Mailing Address: 196-D Castro Street P.O. Box 390640 Mountain View, CA 94041 Mountain View, CA 94039-0640 VM Performance Hotline: 650-964-8867 Fax: 650-964-9012 Web Page: WWW.VELOCITY-SOFTWARE.COM /************************************************************/
