On Fri, Jan 17, 2020 at 5:44 PM DrFranken <midrange@xxxxxxxxxxxx> wrote:
But the VTL vendors like to throw around 100 to 1 so 49 to 1 is clearly
not an unexpected number.
Rob Berendt indicated in his last message that BRMS enables you to select
the date of the file or object that you want to restore. One can imagine a
lot of duplication day by day for objects that don't change regularly. Does
that mean that deduplication applies to objects that are copied to the
cloud only? Or does it apply to objects stored in the VTL? I seem to recall
Cypernetic VTL literature indicating that deduplication is a post-save
operation as opposed to something that occurs during a save. Other
literature indicates that deduplication differs from compression in that
deduplication eliminates duplicate files, while compression eliminates bits
from bytes.
IBM i SAV and SAVLIB commands support the CLEAR(*REPLACE), which if I
understand correctly behaves differently based on whether the output device
is type *OPT or type *TAP. In the case of *OPT, the existing "label" is
replaced, whereas with *TAP, the entire device is cleared. This is a way to
eliminate duplication with *OPT type devices. That was one reason I asked
whether a VTL is categorized as *TAP or *OPT?
midrange.com
