> If I code SPACE=(CYL,(2,2,0)),UNIT=SYSDA is that implicitly a request for > only one volume, or might z/OS give me one cylinder each on two volumes or a > secondary allocation on a second device (assuming, of course, that SYSDA > were multiple volumes, as it usually would be)?
I just tried to get a data set to be multi-volume. The only way I was able to do that is when the first data set is defined with secondary extents *and* those extents were exhausted on the first volume. So I'd say you would get 2+2*16 extents on the first volume, assuming that it is defined *somewhere* that either the unit count is larger than one or a data class is silently assigned that allows multi-volume. Or your application forces FEOV and then (with application support) start writing on the next candidate volume. As far as I know, the only way to get a cylinder (or rather 2 from your example) on each volume before the extents are exhausted is when this is a striped data set. And I don't know (and haven't looked into it) how to define a striped data set. But I know that in my previous shop the system dumps were written striped, and it was something defined somewhere in SMS. Barbara ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
