> John Dawes <mailto:[email protected]> March 31, 2015 at 9:48 AM > G'Day, > > I have to initialise a 3390-9 volume as a PAGE volume. What would be > the ideal size of the VTOC & VVDS? I was thinking 29 tracks for the > VTOC and 15 for the VVDS. Any suggestions? > > Thanks. > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, send > email to [email protected] with the message: INFO IBM-MAIN
>From: IBM Mainframe Discussion List [mailto:[email protected]] On >Behalf Of Mark Jacobs - Listserv >Sent: Tuesday, March 31, 2015 8:53 AM >To: [email protected] >Subject: Re: IDEAL SIZE OF VTOC & VVDS FOR PAGE VOLUME >With one dataset (I'm assuming) on the volume, a one track VTOC is sufficient, >and you really don't need an index on it either. I don't really think you want only 1 page dataset on a 3390-9. However, I agree that a small vtoc and no vtoc index is appropriate. 15 tracks for the VVDS will be overkill. Once IPL'ed, on a dedicated paging volume, the system will (most likely) *NEVER* reference the vtoc again, so the vtoc index is not needed. Since there will be (at most) 1-3 datasets on the volume, a 1 or 2 track vtoc would be sufficient. (PAV will handle IO contention). Since you can't allocate page datasets on other than a cylinder boundary (without committing unnatural acts), tracks 1-14 will be unusable for anything else. I would go with VTOC (000,1,9), no vtoc index, and a VVDS of 5 tracks. This will fill up the 1st cylinder or the volume. Of course, if you put things other than the 1-3 page datasets on the volume, all of the above discussion is moot. BTW, there were (in the last year or so) there were several PTF's regarding creating page datasets w/more than 2048k(?) slots. Sorry don't have the APAR numbers available. HTH, ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
