>From 3 output tapes to 12? What kind of tape drives are you using? Rex
-----Original Message----- From: IBM Mainframe Discussion List [mailto:[email protected]] On Behalf Of McKown, John Sent: Wednesday, September 14, 2011 8:18 AM To: [email protected] Subject: Re: SMS compressed VSAM datasets Given that the most obvious difference is that what used to take 3 output tapes is now going to 12 output tapes, the "slow down" is due to the number of bytes being written to tape. The bytes read from disk seem be about the same because the number of cylinders taken by the VSAM dataset is the same. The "problem" is that Faver is expanding the compressed bytes in the SMS case but not in the Data Accelerator case. We are talking to CA about why Faver expands the compressed bytes when the dataset is SMS compressed instead of just "sucking it up" using something like a "read track" CCW which I think would bypass the SMS decompression. BTW - Faver is working exactly as it is documented to work in the Faver manual. We just don't like it. <shrug> -- John McKown Systems Engineer IV IT Administrative Services Group HealthMarkets(r) 9151 Boulevard 26 * N. Richland Hills * TX 76010 (817) 255-3225 phone * [email protected] * www.HealthMarkets.com Confidentiality Notice: This e-mail message may contain confidential or proprietary information. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. HealthMarkets(r) is the brand name for products underwritten and issued by the insurance subsidiaries of HealthMarkets, Inc. -The Chesapeake Life Insurance Company(r), Mid-West National Life Insurance Company of TennesseeSM and The MEGA Life and Health Insurance Company.SM > -----Original Message----- > From: IBM Mainframe Discussion List > [mailto:[email protected]] On Behalf Of Staller, Allan > Sent: Wednesday, September 14, 2011 7:50 AM > To: [email protected] > Subject: Re: SMS compressed VSAM datasets > > 1) I would increase bufnum before bufsize.... > 2) Compress the output... > > HTH, > > <snip> > This is a weird question, but I've been directed to ask it. We are > converting some VSAM datasets which currently use BMC's Data > Accelerator > compression to use SMS compression instead. This is a financial > decision. We use CA-Faver to do our VSAM backups. Faver states in its > manual that it will unload the VSAM data to its archive in > uncompressed > form. I guess this is because Faver "knows" it is SMS compressed. When > the data was compressed via Data Accelerator, Faver was > unaware that it > was compressed, and so did not interface with Data Accelerator to > uncompress the data. This meant that the data on the tape was > in a very > compressed form. Which is not true with SMS compression. The result of > this difference is that our backups are taking much longer. > Which was a > surprise to all and is causing concern. So my question out > there is "any > ideas on what I can do to make run faster"? So far, the only > suggestion > from CA is to increase the BUFSIZE on the dump. But I don't think this > is going to reduce the run time significantly. > </snip> > > ---------------------------------------------------------------------- > 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 The information contained in this e-mail may contain confidential and/or privileged information and is intended for the sole use of the intended recipient. If you are not the intended recipient, you are hereby notified that any unauthorized use, disclosure, distribution or copying of this communication is strictly prohibited and that you will be held responsible for any such unauthorized activity, including liability for any resulting damages. As appropriate, such incident(s) may also be reported to law enforcement. If you received this e-mail in error, please reply to sender and destroy or delete the message and any attachments. Thank you. ---------------------------------------------------------------------- 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
