It is a parmlib, I don't think the members will be staged to VLF (who would stage them)? Considering the I/O times and the size of the directory, I suppose the directory is the problem. Maybe LLA member caching might help if a BLDL is done to locate a member. Otherwise converting it to PDSE would help with its member caching.
Kees. -----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of Mark Jacobs - Listserv Sent: 28 April, 2016 14:36 To: [email protected] Subject: Re: PDS I/O Performance Improvement Is it defined to VLF? > Kreiter IBM-Main <mailto:[email protected]> > April 28, 2016 at 8:32 AM > 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 > > > Please be alert for any emails that may ask you for login information > or directs you to login via a link. If you believe this message is a > phish or aren't sure whether this message is trustworthy, please send > the original message as an attachment to '[email protected]'. > -- Mark Jacobs Time Customer Service Technology and Product Engineering The standard you walk past is the standard you accept. Lt. Gen. David Morrison ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN ******************************************************** For information, services and offers, please visit our web site: http://www.klm.com. This e-mail and any attachment may contain confidential and privileged material intended for the addressee only. If you are not the addressee, you are notified that no part of the e-mail or any attachment may be disclosed, copied or distributed, and that any other action related to this e-mail or attachment is strictly prohibited, and may be unlawful. If you have received this e-mail by error, please notify the sender immediately by return e-mail, and delete this message. Koninklijke Luchtvaart Maatschappij NV (KLM), its subsidiaries and/or its employees shall not be liable for the incorrect or incomplete transmission of this e-mail or any attachments, nor responsible for any delay in receipt. Koninklijke Luchtvaart Maatschappij N.V. (also known as KLM Royal Dutch Airlines) is registered in Amstelveen, The Netherlands, with registered number 33014286 ******************************************************** ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
