Chuck, I think the copy to VIO suggestion is one of the best here, but you will likely be copying more members than you actually touch along with the directory.
Is the environment one where the JCL command interface, or automation to add the PDS to LLA FREEZE in the step before the job runs, and then remove it when it completes? That would mean a one-time read of the directory only, eliminate all those long key searches for each member, and then just read the members the utility touches. I think this would be the most efficient solution. Ron -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Kreiter IBM-Main Sent: Thursday, April 28, 2016 5:33 AM To: [email protected] Subject: [IBM-MAIN] PDS I/O Performance Improvement Hello, I'm looking for some suggestions on how to possibly improve I/O performance to a PDS. A user is running a job that is reading a large parmlib (through PROJCL I believe). I think the access is random rather than sequential. The parmlib has ~180,000 members is has an LRECL of 80/BLKSIZE of 27,920. The performance team has reviewed a found ~ 6ms response time to the volume that houses the PDS with most of the time being connect time. Thanks, Chuck ---------------------------------------------------------------------- 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
