Standalone DDR hardware assigns question
My searches haven't found anything that answers this question, and perhap s only Alan will know the answer, so here goes: Does Standalone DDR (directly in an LPAR, not under z/VM) do a hardware assign release for the 3590 tape drive addresses it uses? I'm thinking ahead to an upcoming DR exercise in which while I'm running DDR native in one LPAR some z/OS images are being IPL'd in other LPARs that also have access to the same tape drive ranges. I know z/OS does th e hardware assign when it varies the drive online, and I'm wondering if tha t will negatively impact Standalone DDR's access to the tape drive it is using. Once I'm far enough along that I can run DDR under z/VM I know it won't be an issue because z/VM will do the assign when the drive is attached to a virtual machine. Brian Nielsen
Re: Standalone DDR hardware assigns question
On Monday, 04/05/2010 at 01:19 EDT, Brian Nielsen bniel...@sco.idaho.gov wrote: Does Standalone DDR (directly in an LPAR, not under z/VM) do a hardware assign release for the 3590 tape drive addresses it uses? Yes. When running standalone, drives are assigned on first use and unassigned at EOJ. I'm thinking ahead to an upcoming DR exercise in which while I'm running DDR native in one LPAR some z/OS images are being IPL'd in other LPARs that also have access to the same tape drive ranges. I know z/OS does the hardware assign when it varies the drive online, and I'm wondering if that will negatively impact Standalone DDR's access to the tape drive it is using. Once I'm far enough along that I can run DDR under z/VM I know it won't be an issue because z/VM will do the assign when the drive is attached to a virtual machine. Yes, it will be an impact; MVS has to unassign the drives that DDR wants to use, if he has already assigned them (first one up wins). If you have z/VM up and a good quality tape management product running, it can talk to z/OS and get the drives unassigned, depending on what tape management software you have running on z/OS. For SA DDR, you will have to manually take them offline from MVS before you run DDR. Alan Altmark z/VM Development IBM Endicott
Re: Standalone DDR hardware assigns question
On Mon, 5 Apr 2010 14:01:32 -0400, Alan Altmark alan_altm...@us.ibm.com wrote: On Monday, 04/05/2010 at 01:19 EDT, Brian Nielsen bniel...@sco.idaho.go V wrote: Does Standalone DDR (directly in an LPAR, not under z/VM) do a hardwar e assign release for the 3590 tape drive addresses it uses? Yes. When running standalone, drives are assigned on first use and unassigned at EOJ. Thanks. Exactly what I needed to know, and as I hoped. Brian Nielsen
