We used to DEDICATE the packs to the MVS or VSE images running
underneath and share across physical CECs (3090 days).

-----Original Message-----
From: The IBM z/VM Operating System [mailto:[EMAIL PROTECTED] On
Behalf Of Alan Altmark
Sent: Thursday, April 10, 2008 3:38 PM
To: [email protected]
Subject: Re: Ten Questions to ask a Prospective z/VM Systems Programmer

On Thursday, 04/10/2008 at 02:54 EDT, "Quay, Jonathan (IHG)" 
<[EMAIL PROTECTED]> wrote:
> To share with other LPARS you need REAL reserve/release, which I think
> entails coding SHARED in on the RDEV in the system configuration file.

1. The MDISK must be defined as MWV.  If you don't do that, the virtual 
machine will get a COMMAND REJECT on a RESERVE CCW.

2. A successful RESERVE is always enforced on the local VM system.
Always.

3. If the MDISK is a fullpack minidisk (DEVNO or 0-END) then the
minidisk 
is ELIGIBLE for real RESERVE/RELEASE.

4. If the volume containing the mdisk is defined as SHARED in SYSTEM 
CONFIG or via SET SHARED ON, a virtual R/R will be enforced locally AND
a 
real R/R will flow to the volume.

So the only case where a real Reserve/Release is used is MWV + fullpack
+ 
SHARED.

Alan Altmark
z/VM Development
IBM Endicott

Reply via email to