Does it really make a difference? IIRC, starting with 3490, the control unit compressed and buffered the data and then wrote to the physical tape in a fixed, very large block size. This being the case, block size only impacts the channel utilization and with fiber channels, I have not seen this to be an issue.
Dennis Roach GHG Corporation Lockheed Martin Mission Services Flight Design and Operations Contract NASA/JSC Address: 2100 Space Park Drive LM-15-4BH Houston, Texas 77058 Mail: P.O. Box 58487 Mail Code H4C Houston, Texas 77258 Phone: Voice: (281)336-5027 Cell: (713)591-1059 Fax: (281)336-5410 E-Mail: [email protected] All opinions expressed by me are mine and may not agree with my employer or any person, company, or thing, living or dead, on or near this or any other planet, moon, asteroid, or other spatial object, natural or manufactured, since the beginning of time. > -----Original Message----- > From: IBM Mainframe Discussion List [mailto:[email protected]] On > Behalf Of Lizette Koehler > Sent: Thursday, March 26, 2009 12:22 PM > > I am going to be doing an analysis on our tapes to see if they are > optimally blocked. We are using VTS that looks like 3490E tapes. > > Is there a good rule of thumb for all datasets on tape - that to be > blocked optimally use X? > > The lrecls on these tape range from 80 to 10399 > > Lizette ---------------------------------------------------------------------- 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
