I've searched high and low for an answer to this question and I couldn't find one before posting. Happy to be proved wrong though of course!
My question is, how are transforms performed and subsequently, how much space is required during the transform? Are transforms performed "in-place" i.e. vbk merged with vib? Some of the documentation alludes to this. Or is a new file created and the vbk and vib merged into the new file?
Thus my second question - how much space is required for the transform if it's not done in-place? 100% of (vbk size + vib size)? And how much space is required if it is done in-place? Technically, none as the two files are merged?
Thanks in advance (and apologies if this has been answered before).
Well I know that for backup copy GFS schemes the full is just pulled out of the simple retention and marked as weekly/monthly/quarterly/etc so that's self-explanatory. But for the other transform types, they all involve some level of merging so all of the above (except for GFS), please
During synthetic full, an entirely new VBK file is created from the previous VBK and corresponding VIB files, all of which then are transformed to VRB files, so you do need space for the new full (however most of the space is released after transformation).
During reversed incremental, as well as backup copy simple retention cycle, changes are “injected” directly into VBK file replacing the existing changed blocks, so the required space is not that essential.