John, Since in z/OS 1.8 and above there is no such thing as a physical swap of an address space, I see no reason to use the SWAP parameter.
Wayne Driscoll Product Developer NOTE: All opinions are strictly my own. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[EMAIL PROTECTED] On Behalf Of Chase, John Sent: Thursday, March 20, 2008 9:25 AM To: [email protected] Subject: Define Pagespace -- SWAP vs NOSWAP? Hi, All, We're renovating our page dataset allocations (z/OS 1.7 -> 1.9) and found that our previously-used DEFINE specs from "many moons ago" need "tweaking" beyond space and volser; specifically, SWAP vs NOSWAP. From reading the following: SWAP|NOSWAP specifies whether page space is defined for local system queue area (LSQA) pages or for pageable private area pages. (Auxiliary storage management separates private area address space pages into LSQA pages and pageable private area pages.) SWAP Specifies that the page space is a high-speed data set used during a swap operation to store and retrieve the set of LSQA pages owned by an address space. NOSWAP Indicates that the page space is a conventional page space used to record pageable private area pages. It appears that we should take the default of NOSWAP for our LOCALs and PLPA/COMMON datasets. But since we don't currently "swap-out" address spaces like "in the old days" (we don't have any specific SWAP datasets), should we consider defining a subset of our new page datasets with the SWAP parameter? If so, how many or what proportion? Since nowadays just about everything is a "high-speed data set" (device), would it make a measurable difference one way or the other? Any advice / recommendations / caveats would be appreciated. TIA, -jc- ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
