There was a lot of discussion at the last Share about how store in instruction stream (SIIS) can be a drag on performance. An MXG report revealed we have a high SIIS percentage in our zIIP's but the only thing running of note at the time was Virtual Tape for Mainframe (VTFM).
Someone told me a while ago that VTFM dynamically changes channel programs in memory to redirect tape I/O to DASD. Is that true? If it is, would said jimmying of channel programs drive high SIIS percentages? Thanks. Robert Crawford Mainframe Management United Services Automobile Association (210) 913-3822 "Est multum ineptias atque in volumine petram et de illius ineptias est pulchellus frigus." - Virgil Please send requests to Mainframe Management through our front door at go/mfm ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO IBM-MAIN
