On Monday, 01/21/2008 at 10:02 EST, "Dale R. Smith" <[EMAIL PROTECTED]> wrote:
> The x'05050505' in the KEY area indicates that this is a Format-5 DSCB. > Immediately following the key identifier, the x'0001' is the first free > track available, (relative to the beginning of the volume). The x'0000' > after that is the number of free cylinders in the extent, in this case > zero. The x'00' after that is the number of additional free tracks, also > zero. Other free extents would follow this one, (there are none). This > Format-5 DSCB indicates that there is NO free space on this volume, which > is what z/OS would believe also. Your observations match mine from last Friday http://listserv.uark.edu/scripts/wa.exe?A2=ind0801&L=ibmvm&T=0&P=32477 > My guess is that DITTO may be looking > for Format-1 and Format-3 DSCBs, (they describe space used by allocated > datasets), and not finding any on a VM volume, it is a assuming that the > entire volume is free. z/OS will not allocate a dataset on a properly > formatted VM volume, regardless of what DITTO shows. (whew!) I'm glad its a DITTO bug. It explains why my playing with the Format-5 DSCB didn't affect what DITTO reported. I looked up the S213-04: It is because a format *1* DSCB cannot be found. I was confusing the lack of a dataset called SYS1.VTOC with the lack of a VTOC. Tricksy, it is! Alan Altmark z/VM Development IBM Endicott
