On Friday, 08/05/2011 at 02:31 EDT, "Martin, Terry R. (CMS/CTR) (CTR)" <terry.mar...@cms.hhs.gov> wrote:
> Does the RESERVE work the same for z/OS? Yes. This isn't an OS-specific phenomenon. As Bruce indicated, when you identify memory as "reserved" in the image profile, it's just a reservation. No guarantees that you're going to get it. Memory that is configured on the box and is available to satisfy reservations is detected by the OS as "standby". As the various LPARs bring standby memory online, the standby pool is drained. If you see STANDBY fall below your RESERVED amount, then you better hurry. During POR, you can actually see the transition of memory from RESERVED to STANDBY. LPARs are activated as soon as a chunk of central storage has passed POR checks. While the LPAR is activating, the hardware continues validating memory, activating LPARs as it goes. Eventually, it stops activating LPARs, and the remainder of the memory is validated and placed in the STANDBY pool. This process takes time, so beware that VARY STORAGE may fail when issued immediately after POR since the standby pool may not yet be full enough to satisfy your request. Alan Altmark Senior Managing z/VM and Linux Consultant IBM System Lab Services and Training ibm.com/systems/services/labservices office: 607.429.3323 mobile; 607.321.7556 alan_altm...@us.ibm.com IBM Endicott
