> The key point is to ensure that the entire > disk is CP-formatted with the CPVOL FORMAT command in ICKDSF (CPFMTXA > calls DSF under the covers) before you let CP try to page to it.
Actually, the key point is: Ensure that the cylinders you _FORMAT_ with CPFMTXA for CP's use (as PAGE, SPOL, DRCT) match exactly the cylinders that you _ALLOCATE_ with CPFMTXA for those uses. You can always run CPFMTXA, and choose ALLOCATE to see how it is allocated. But unfortunately, other than checking console logs I know of no way to see if a cylinder was actually CP-formatted. IMHO, and as David implies, formatting new DASD specifying 0-END and *then* performing the ALLOCATE is a good practice - even if you don't actually plan to use all of the DASD for CP's use. By ensuring that the cylinder formatting and allocation mapping match, you avoid the situation where you missed formatting a single cylinder. Been there, done that - forgetting to include cylinder zero in the total cylinder count back in my young pup days (i.e. a 3390-3 has 3339 cylinders, but ends with cylinder 3338). Format 0-END and you should be safe ... unless some other system writes to the volume, or (*perhaps*) if you DDR a DASD to a larger DASD and without formatting the larger space, simply ALLOCATE the new cylinders as a CP-used allocation (PAGE, SPOL, DRCT). We don't need to say that one should never, ever format CP-allocated cylinders that are currently in use by a running system, even to fix a problem, right? No, I didn't think so. :-) Mike Walter Hewitt Associates Any opinions expressed herein are mine alone and do not necessarily represent the opinions or policies of Hewitt Associates. "David Boyes" <[EMAIL PROTECTED]> Sent by: "The IBM z/VM Operating System" <[email protected]> 01/08/2008 10:48 AM Please respond to "The IBM z/VM Operating System" <[email protected]> To [email protected] cc Subject Re: z/VM 5.2 Absurd System shutdown - PJBR > So, we're going to define a new page device equally directory-defined as > 520PAG (that is, 0-END), then we're going to CPFMTXA FORMAT it and then > ALLOCATE 1-3338 this time. That's the correct process. The key point is to ensure that the entire disk is CP-formatted with the CPVOL FORMAT command in ICKDSF (CPFMTXA calls DSF under the covers) before you let CP try to page to it. The cyl 0 vs 1 discussion is just a safety measure; CP is usually smart enough not to shoot itself in the head by paging onto the volume label & allocation bitmap that tells it where it paged stuff...8-) The information contained in this e-mail and any accompanying documents may contain information that is confidential or otherwise protected from disclosure. If you are not the intended recipient of this message, or if this message has been addressed to you in error, please immediately alert the sender by reply e-mail and then delete this message, including any attachments. Any dissemination, distribution or other use of the contents of this message by anyone other than the intended recipient is strictly prohibited. All messages sent to and from this e-mail address may be monitored as permitted by applicable law and regulations to ensure compliance with our internal policies and to protect our business. Emails are not secure and cannot be guaranteed to be error free as they can be intercepted, amended, lost or destroyed, or contain viruses. You are deemed to have accepted these risks if you communicate with us by email.
