On 8 November 2012 16:31, Ingo Adlung <[email protected]> wrote: >> PS No, dasdfmt does not do a verify. There is a bit of reading >> afterwards, but that's it. ICKDSF however does do a verify. > > Interesting, isn't end-to-end data checking provided by FICON I/O about > there not being a need for data verification? At the time you wrote the > data and got a successful completion status you know it ended up fine on > the device? i.e. verification only satisfying paranoia?
ICKDSF was written in the days where the operator had to turn the platters by hand (like DJ's do these days). ;-) I was thinking that the verify would be cheap with the track still in control unit cache. But I now notice that ICKDSF does know how to do multiple tracks in one I/O, so I need to dig deeper to understand why it's not significantly faster. Rob ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [email protected] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For more information on Linux on System z, visit http://wiki.linuxvm.org/
