Perhaps the citation looked for is: ============================================================= SPEED|RECOVERY Specifies whether the data component's control areas are to be preformatted This parameter is only considered during the actual loading (creation) of a data set. Creation occurs when the data set is opened and the high-used RBA is equal to zero. After normal CLOSE processing at the completion of the load operation, the physical structure of the data set and the content of the data set extents are exactly the same, regardless of which option is used. Any processing of the data set after the successful load operation is the same, and the specification of this parameter is not considered. If you use RECOVERY, the initial load takes longer because the control areas are first written with either empty or software end-of-file control intervals. These preformatted control intervals are then updated, using update writes with the data records. When SPEED is used, the initial load is faster. SPEED Does not preformat the data component's space. If the initial load is unsuccessful, you must load the data set again from the beginning because VSAM cannot determine the location of your last correctly written record. VSAM cannot find a valid end-of-file indicator when it searches your data records. RECOVERY Does preformat the data component's space prior to writing the data records. If the initial load is unsuccessful, VSAM can determine the location of the last record written during the load process. =============================================================
Don > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] > On Behalf Of Mike Schwab > Sent: Monday, June 03, 2013 6:39 PM > To: [email protected] > Subject: Re: Citation for reformatting of VSAM, HFS and zFS data sets > > I went through the z/OS 1.13 manuals on defining VSAM datasets, but > even where the internal pointers were mentioned, it didn't say each CA > and CI was written as empty when defined. Just explained what was > there in each CI. > > On Mon, Jun 3, 2013 at 1:29 PM, Shmuel Metz (Seymour J.) > <[email protected]> wrote: > > I am editing a wiki article on disk formatting and have been > > challenged to provide documentation of my claim that formatting a VSAM > > cluster, HFS or zFS rewrites existing data. I could cite dead tree > > documentation for VSAM in OS/VS2 R3.8, but I'd really prefer something > > recent enough to be available online, preferably current, and that > > wouldn't include the Unix file systems. I would appreciate it if > > someone could add appropriate citations to > > <http://en.wikipedia.org/wiki/Disk_formatting> or give me the links so > > that I can do so. Thanks. > > > > -- > > Shmuel (Seymour J.) Metz, SysProg and JOAT > > ISO position; see <http://patriot.net/~shmuel/resume/brief.html> > > We don't care. We don't have to care, we're Congress. > > (S877: The Shut up and Eat Your spam act of 2003) > > > > ---------------------------------------------------------------------- > > For IBM-MAIN subscribe / signoff / archive access instructions, > > send email to [email protected] with the message: INFO IBM-MAIN > > > > -- > Mike A Schwab, Springfield IL USA > Where do Forest Rangers go to get away from it all? > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to [email protected] with the message: INFO IBM-MAIN ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
