>> This is a good approach, but please one reminder. The DAT structures >> for virtual disk in storage address spaces, including PGMBKs, are not >> pageable (user space PGMBKs are). And prior to z/VM 5.3.0, they must >> reside in real memory below 2GB. So 275GB of vdisk would be more than >> 2GB of memory required below 2GB for the DAT structures. One would >> want to be on z/VM 5.3.0. The PGMBKs are not reflected in the PTRM >> numbers. > >But only when used, isn't it? >As long as you have not touched them, there's no PGMBKs except for the >first one. Once he actually starts using them I would think that 550 >GB of paging space might approach some other limitations in CP (though >with 3390-9 not the number of cpowned volumes).
It's been a long time since I looked at the code, so I am not certain of all the cases that trigger creation of the DAT structures. I do recall that there were cases where they could be created without the actual virtual disk block being referenced. Like I said, it's not a bad idea, I just don't want anyone who's not on 5.3.0 to be caught by surprise. Bill Bitner - VM Performance Evaluation - IBM Endicott - 607-429-3286 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
