Sent on the Sprint® Now Network from my BlackBerry® -----Original Message----- From: Alan Altmark <alan_altm...@us.ibm.com> Sender: The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU> Date: Fri, 20 May 2011 13:45:14 To: <IBMVM@LISTSERV.UARK.EDU> Reply-To: The IBM z/VM Operating System <IBMVM@LISTSERV.UARK.EDU> Subject: Re: DASD HA & R0 ?
On Friday, 05/20/2011 at 11:55 EDT, "Schuh, Richard" <rsc...@visa.com> wrote: > I think I remember R0 being referred to as the Track Capacity record. It was > not a constant, but held the remaining capacity after the last formatting write. It is possible that some OSes write things to R0, but CMS and CP don't. CMS FORMAT and DSF write R0 and HA with zeros. Use DDR "PRINT 0 0 0" to see them. Each time you WRITE R0, you erase the track. Track capacity is determined by using formulae described in the book with data from the READ DEVICE CHARACTERISTICS command. Alan Altmark z/VM and Linux on System z 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
